Research Article

Performance Evaluation of Sub1 Rice Genotypes for Vegetative Stage Submergence Stress and Reproductive Stage Drought Stress

Ifrah Amjad1, Muhammad Nouman Khalid1*, Muhammad Kashif1, Muhammad Noman1, Sajid Ali2, Rizwan Ahmed Shaikh3, Muhammad Babar4, Muhammad Asim Bhutta5 and Amna Bibi5

1Department of Plant Breeding and Genetics, University of Agriculture Faisalabad, Pakistan; 2Soil and Water Testing Lab Toba Tek Singh, Punjab- Pakistan; 3Department of Horticulture, Sindh Agriculture University Tandojam, Pakistan; 4Department of Agriculture, University of Swabi, Khyber Pakhtunkhwa, Pakistan; 5Cotton Research Institute, Multan, Pakistan.

Received | August 16, 2022; Accepted | September 03, 2022; Published | December 02, 2022

*Correspondence | Muhammad Nouman Khalid, Department of Plant Breeding and Genetics, University of Agriculture Faisalabad, Pakistan; Email: noumankhalidpbg@gmail.com

Citation | Amjad, I., M.N. Khalid, M. Kashif, M. Nauman, S. Ali, R.A. Shaikh, M. Babar, M.A. Bhutta and A. Bibi. 2022. Performance evaluation of Sub1 rice genotypes for vegetative stage submergence stress and reproductive stage drought stress. Sarhad Journal of Agriculture, 38(5): 240-251.

DOI | https://dx.doi.org/10.17582/journal.sja/2022/38.5.240.251

Keywords | Rice, Sub1 gene, Submergence, Drought

Copyright: 2022 by the authors. Licensee ResearchersLinks Ltd, England, UK.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

Introduction

Rice (Oryza sativa L.) is widely cultivated around the globe extending from 50° north to 35° south. However, it is most susceptible crop to almost 42 different biotic (like bacterial leaf blight, sheath blight, blast and brown spot etc.) and abiotic stresses like drought, salinity, high and low temperatures etc. (Bhutta et al., 2019). It is typically cultivated in partial flooding conditions (Barik et al., 2019). However, flash floods severely damage the standing crop as entire plant becomes completely submerged in water (Woolston, 2014). The rice plant elongates its leaves and stems during flooding so as to evade submergence (Mori et al., 2019). Varieties of deepwater rice can do that quickly to survive (Akhter et al., 2019). Most of the rice cultivars die within seven to fourteen days of complete submergence by damaging cell membrane system, increasing biofilm fluidity, intensifying anaerobic respiration and changing metabolic balance, eventually leading to metabolic abnormalities (Xiong et al., 2019). Flash floods also cause significant crop damage at germination level and early seedling level leading to poor plant standing (Mahmood et al., 2019). It is frequent in uneven irrigated land and flood-prone rainfed ecosystems in a condition where rainfall occurs shortly after the seeding of rice (Tiwari, 2018). Yield loses due to flash floods depends on depth, duration, temperature and turbidity of flood water, soil fertility, fertilizer, seedling density, and age of the crop (Afrin et al., 2018).

Drought is another important problem in rice production (Mohanty et al., 2013). Drought stress not only reduces the grain yield but also affect the grain quality drastically. It reduces the dry matter accumulation in all plant organs and shortens the life cycle of the plant. It can occur at any growth stage of the crop (Upadhyaya and Panda, 2019). At vegetative stage drought stress reduces the growth of photosynthetic and storage organ of plant. Reproductive stage is most critical stage to drought stress (Hazman et al., 2019). At the time of flowering, it may limit the viability of pollen grains, receptivity of stigmas and seed setting (Korres et al., 2017). Thus, drought stress at reproductive stage affects the process of grain development resulting into spikelet sterility which ultimately reduces the yield (Swain et al., 2017; Bhutta et al., 2019). Submergence and drought stress can also occur successively within one season (submergence followed by drought and vice versa). An example happened in Luzon, Philippines, in 2006. During wet-season crop, seasonal rainfall surpassed 1,000 mm and within the same season a short spell of drought at flowering stage caused a dramatic decline in grain yield and harvest index (Mohanty et al., 2013).

To cope up the abrupt changes in climate, there is a dire need to develop high yielding cultivars which can tolerate multiple abiotic stresses (Arif et al., 2019). For this purpose, many scientists studied the genetic mechanisms involved in tolerance to submergence and drought stress. Submergence tolerance in rice is mainly controlled by a single locus present on chromosome 9 carrying cluster of three genes (Sub 1, Sub1B and Sub1C) which encode ethylene-response factors and are activated under flooding conditions (Septiningsih et al., 2015; Azarin et al., 2017; Dixit et al., 2017). Reports have shown that Sub1 gene has pleiotropic effects on submergence and drought (Xiong et al., 2019). Rice genotypes having Sub1 overcome this inevitable stress following de-submergence because it plays a pivotal role in detoxification of reactive oxygen species and stress inducible gene expression during drought (Fukao et al., 2011). These genotypes become able to form new leaves after stress. Thus, Sub1 not only provides robust submergence tolerance but also improves survival of rapid dehydration following de-submergence and water deficit during drought (Bin-Rahman and Zhang, 2016). The present study was conducted to identify the genotypes having Sub1 gene showing tolerance to not only the submergence stress but also the drought stress under field conditions in rice.

Materials and Methods

Experimental site and plant materials

The experiment was conducted in the fields of Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad during kharif season 2019. The plant materials was collected from Plant Breeding and Genetics Division (PBGD) which was comprised of five genotypes having sub-1 gene (FR-13A, Swarna-Sub1, IR-44-Sub1, IR-07-F289-Sub1, Ciherang-Sub1), two high yielding local cultivars (KSK-133, Super Basmati) and drought tolerant and drought susceptible checks (Nagina-22 and IR-64, respectively) (Mathan et al., 2021). The field experiments were laid out in split plot design with three replications. The genotypes were taken as sub plot factor while stress was taken as main plot factors. The row to row and plant × plant spacing was 9 inches. Gap-filling was also practiced as required after transplanting in order to ensure 100% plant establishment. All the necessary agronomic practices were performed during plant growth in normal and submerged conditions. Seeds were sown on the wet raised beds and 35 days seedlings were transplanted to well puddled soil.

Experiment 1: Survivability and shoot elongation rate of rice genotypes under complete submergence

Five Sub1 genotypes along with two high yielding local cultivars (KSK-133 and Super Basmati) were evaluated under complete submergence stress. Three seedlings were transplanted in each pot. The pots were filled with dried soil from the paddy fields. Then, puddling of soil was done by adding water. Thirty-five days old seedlings were transplanted in the pots (3 plants per pot). The experiment was laid out in split plot design with three replications. After transplanting, 2 grams of urea + DAP were added in each pot. The seedlings were allowed to recover from transplanting shock for ten days. After ten days of transplanting, the pots were submerged completely in an outdoor concrete tank for 14 days. The water used for flooding was static, clean tube well water. No water changes were done during the stress conditions. After de-submergence, plants were allowed to recover for seven days and then data related to number of plants survived were recorded. Plant height of each genotype was also measured one day before submergence and one day after de-submergence.

Observations

• Elongation (per day) = (Plant height after de-submergence – Plant height before submergence)/No. of days submerged.
• Elongation % = {(Plant height after de-submergence – Plant height before submergence)/ Plant height before submergence.} ×100
• Survival % = {(No. of plants before submergence – No. of dead plants)/No. of plants before submergence} ×100

Experiment 2: Evaluation of rice genotype under complete submergence in field conditions

A field experiment was conducted to evaluate the impact of submergence on yield and yield contributing traits of rice. For this purpose, five sub-1 genotypes along with two high yielding local cultivars (KSK-133 and Super Basmati) were evaluated under field conditions. All genotypes were evaluated in a natural water pond for a period of 21 days. The transplanted seedlings were allowed to establish their roots and to recover from transplanting shock for 20 days before submergence. Then, seedlings were completely submerged by filling the pond with normal canal water for 21 days. The stress was maintained by adding water at daily basis in the pond to overcome the water loss due to percolations or evaporation. The cutting of leaves of plant above the water surface was also done twice in whole stress period to ensure the complete submergence of plant. After completing 21 days of complete submergence, the stress was terminated by draining water out of the pond.

Experiment 3: Evaluation of rice genotype under drought in field conditions

A field experiment was carried out to test the hypothesis that genotypes having Sub-1 gene can also survive during drought stress. Five Sub1 genotypes were evaluated. Nagina-22 and IR-64 were grown as tolerant and sensitive checks respectively, as both genotypes were frequently used in the past as checks during screening and also in numerous morpho-physiological studies. The drought stress conditions were made by stopping normal irrigation at booting stage for 30 days.

Observations recorded

The chlorophyll content was measured by the SPAD-502 Plus and leaf area was measured by portable leaf area meter AM300 at the heading stage of the plants. At the time of harvesting, plant height (cm), productive tillers per plant, primary branches per panicle, filled spikelets per panicle, unfilled spikelets per panicle, fertility percentage, panicle length (cm), biological yield per plant (g), grain yield per plant (g) and harvest index were measured.

Statistical analysis

The data of both submergence and drought stress experiments was analyzed by analysis of variances (Steel et al., 1997; Ostertagova and Ostertag, 2013), Tuckey mean comparison tests (Tuckey, 1949) and Dunnett multiple comparison test (Dunnett, 1955) by Statistix 8.1.

Results and Discussion

Survivability and shoot elongation rate of rice genotypes under complete submergence

Shoot elongation rate (elongation per day) of different genotypes under submergence stress was ranged from 0.12 cm to 1.44 cm. Minimum elongation per day was observed in Ciherang Sub1 (0.12 cm) followed by IR-44 Sub1 (0.18cm) and IR-07-F289 Sub1 (0.182cm). Highest elongation per day under complete submergence stress was exhibited by KSK-133 (1.44cm) and Super Basmati (1.27cm). Submergence stress enhanced the plant height of all genotypes ranging from 7.32% to 83.94%. The height of Sub1 genotypes increased within the range of 7.32% (exhibited by CiherangSub1) to 53.25% (exhibited by FR-13-A Sub1). While KSK-133 and Super Basmati exhibited 83.94% and 77%, respectively (Table 1). Percentage survival of all genotypes upon de-submergence was varied from 33.33% (observed in CiherangSub1) to 77.78% (exhibited by IR-07-F289-Sub1). Survival percentage of KSK-133 was 55.56% and of Super basmati was 44.44% (Table 1).

Analysis of variance and mean performance of genotypes for yield and yield related traits under submergence

Results of ANOVA under submergence stress in field conditions revealed that chlorophyll contents, plant height, number of productive tillers per plant, panicle length, total spikelets per panicle and number of grains per panicle showed significant results. Whereas, leaf area, number of primary branches per panicle, number of sterile spikelets per panicle, spikelet fertility percentage, biological yield per plant and grain yield per plant were not significantly affected by submergence stress. The genotypes × treatment interaction was also highly significant for plant height, total spikelets per panicle, number of grains per panicle number of sterile spikelets per panicle, spikelet fertility %, gain yield per plant, harvest index and 1000 grain weight (g) revealing that the joint effect of genotypes and treatment levels on these traits were higher than their individual effects (Table 2).

Post hoc test (Table 3) revealed that the mean values for chlorophyll contents under submergence stress were greater than the normal conditions (Table 3). The chlorophyll contents were ranged from 39.11 (observed in KSK-133) to 42.81 (observed in Super Basmati) under submergence. While under normal conditions, maximum chlorophyll contents were observed in Swarna Sub1 (44.45) followed by KSK-133 (40.36) and IR-07-F289 Sub1 (39.77). Leaf area was ranged from 2726 m2 to 3843.33 m2 under submergence stress and 2895.66 m2 to 4335 m2 under normal conditions. Maximum plant height was observed in Super Basmati (121.04 cm) followed by KSK-133 (117.89 cm) and minimum plant height was observed in Swarna Sub1 (75.91 cm). When the mean values of all the genotypes for number of productive tillers were compared, it was revealed that highly significant results were due to super basmati which was significantly different from KSK-133 and Ciherang Sub1. Panicle length was ranged from 21.3 cm to 25.77 cm under normal conditions while 21.38 cm to 24.94 cm under submergence stress. The significance of genotypes primary branches per panicle was only due to the Swarna Sub1. Mean values of number of grains per panicle were ranged from 85.06 to 184.26 under normal conditions while 102.11 to 126.88 under submergence stress. Maximum number of sterile spikelets were observed in Swarna Sub1 (28.88) followed by IRR-44 Sub1 (20.44) and Super Basmati (12.11) while minimum mean values were observed for IR-07-F289-Sub1 (4.77). Mean values of fertility % were varied from 79.08 % to 96.74 % under normal conditions while from 81.45 % to 95.53 % under submergence conditions. Post hoc test also revealed that the all the genotypes under study had grain yield different from one another. Swarna Sub1 exhibited highest grain yield (25.64g) under stress followed by Ciherang Sub1 (24.13g). Under complete submergence stress, maximum value for harvest index was observed in Super Basmati (42.92 g) and minimum value was observed in IR-07-F289 Sub1 (34.64 g).

 

Table 1: Elongation per day, elongation % and survival % of rice genotype under complete submergence.

S. No.	Varieties	Plant height before stress (cm)	Plant height after stress (cm)	Elongation per day (cm)	Elongation %	Survival %
1	FR-13A Sub 1	32.3	49.5	0.95	53.25	55.56
2	Swarna Sub 1	22.57	26.5	0.21	17.41	66.67
3	IR-44 Sub 1	26.94	30.33	0.18	12.58	33.33
4	IR-07-F289 Sub 1	30.04	44.83	0.182	49.23	77.78
5	Ciherang Sub 1	30.43	32.66	0.123	7.32	33.33
6	KSK-133	30.77	56.6	1.44	83.94	55.56
7	Super Basmati	29.66	52.5	1.27	77	44.44

 

 

 

Analysis of variance and mean performance of genotypes for yield and yield related traits under drought

Results of ANOVA revealed that drought stress severely reduced the chlorophyll contents, plant height, panicle length, number of primary branches per panicle, total spikelets per panicle, number of grains per panicle, number of sterile spikelets per panicle, spikelet fertility percentage, grain yield per plant and harvest index. While leaf area, number of productive tillers per plant and biological yield per plant remain unaffected (Table 4). The genotypes × treatment interaction was also highly significant for all traits under study except panicle length, number of grains per panicle and biological yield per plant (Table 4).

Tuckey post hoc test showed that for chlorophyll contents, variation among genotypes came from three homogeneous groups (a, b and ab) which were significantly different from each other (Table 5). Plant height under drought stress was ranged from 50.65 cm to 81.88 cm while under normal conditions it ranged from 73.13 cm to 143.73 cm. Post hoc test revealed that all genotypes were divided into 4 groups (a, b ab, and c) for productive tillers per plant. Maximum panicle length was observed in IR-64 (31.42 cm) followed by Ciherang Sub1 (22.84 cm) under normal conditions. While under stress conditions panicle lengths varied from 15.41 cm to 25.4 cm. When post hoc test was applied for primary branches per panicle, it revealed that the significant results of genotypes were only due to Swarna Sub1 because this was the only genotype which was significantly different from other genotypes for primary branches per panicle. Under drought stress maximum sterile spikelets were produced by susceptible check IR-64 (101.83). The above ground biomass was varied from 48.8 g to 118.93 g under normal conditions and 29.66 g to 112.93 g under drought stress. Under normal conditions grain yield per plant was ranged from 18.85 g (observed in Swarna Sub1) to 38.03 g (observed in Nagina-22) and under drought stress it varied from 0.98 g (exhibited by IR-44 Sub1) to 5.13 g (observed in Swarna Sub1). Maximum yield reduction was observed in IR-64 (-96.52 %) as it was taken as drought susceptible check. When means of genotypes compared, it revealed that genotypes were distributed among four groups for harvest index. Maximum harvest index was observed in Ciherang Sub1 (51.18 g) followed by IR-44 Sub1 (45.24 g) under normally irrigated conditions. While under drought, its values varied from 0.96 g to 13.94 g. Minimum decrease in harvest index under drought was observed in IR-07-F289 Sub1 (-44.64 %) followed by Swarna Sub1 (-64.15%).

Two-sided dunnett’s multiple comparisons for yield and yield related traits under drought stress

Dunnett’s multiple comparison test revealed chlorophyll contents of all genotypes were not significantly different from Nagina-22 (which was used as tolerant check) under drought conditions (Table 6). IR-07-F289 Sub1 and IR-64 had significantly more leaf area than Nagina-22 under drought stress while IR-44 Sub1 had significantly less leaf area than Nagina-22. The mean values of plant height of all Sub1genotypes were significantly less than nagina-22. While IR-64 had plant height comparable to nagina-22. IR-44 Sub1 and Ciherang Sub1 produced more number of productive tillers per plants as compare to Nagina-22, while the mean values of Swarna Sub1 and IR-07 F289 Sub1 were comparable to the mean value of Nagina-22. The susceptible check (IR-44) had lowest number of productive tillers per plant among all genotypes under drought. Panicle lengths of all Sub1 genotypes were comparable to Nagina-22 because the differences were non-significant. Swarna Sub1 exhibited more primary branches per panicle as compared to the Nagina-22 under drought conditions. The mean values of total number of spikelets per panicle under drought conditions for all genotypes were compared with the Nagina-22. The mean values of total numbers of spikelets per panicle of all Sub1 genotypes showed non-significant differences when compared with Nagina-22. The susceptible check IR-64 had maximum number sterile of spikelets per panicle and also were higher than Nagina-22 under drought conditions (Table 6). Swarna Sub1 and IR-07-F289 Sub1 performed comparable to Nagina-22 under drought stress while Ciherang Sub1 and IR-44 Sub1 had significantly very low fertility percentage as compare to the Nagina-22. The mean values of all Sub1 genotypes were significantly less than Nagina-22 for biological yield per plant. Swarna Sub1 had more grain yield under drought conditions as compare to Nagina-22. While CiherangSub1 had almost similar grain yield to the Nagina-22. Swarna Sub1 and IR-07-F289 Sub1 had significantly more harvest index than Nagina-22 under drought stress while CiherangSub1 and IR-44 Sub1 had comparable value to the Nagina-22.

 

 

 

Table 6: Two-sided dunnett’s multiple comparisons for yield and yield related traits under drought.

Genotypes	Nagina-22	Swarna Sub1	IR-44-Sub1	IR-07-F289-Sub1	Ciherang Sub1	IR-64
Chlorophyll contents	33.24	34	34.18	34.08	34.11	39.06
Leaf area (m2)	3564.7	3867.7	2278.7-*	4752.7*	2952	6142.7*
Plant height (cm)	76.66	50.65-*	56.75-*	58.31-*	56-*	81.66
Productive tillers per plant	13.66	10.5	18.83*	9.33	19.5*	8.66-*
Panicle length (cm)	15.42	14.5	19.21	18.26	19.2	25.42*
Primary branches per panicle	7.33	10.5*	8.66	8.83	7.33	8.83
Total spikelets per panicle	87.33	97.17	69.67	78	89	157.30*
Number of sterile spikelets per panicle	109.92	90.32	45.62	72.63	104.48	113.48
Spikelet fertility %	17.17	30	63.5	19	64.5	101.83*
Primary branches per panicle	81.44	68.55	8.93-*	76.01	28.65-*	32.94-*
Biological yield per plant (g)	106.57	39.63-*	29.67-*	35.83-*	49.20-*	112.93
Gain yield per plant (g)	3.17	5.13*	0.98-*	3.93	2.31	1.07-*
Harvest index	3.02	13.09*	3.48	13.94*	4.85	0.96

*Indicates a significant difference from Nagina-22 at 95% probability level.

 

Global climate change has an impact on the frequency and magnitude of hydrological fluctuations, which can result in catastrophic events such as floods and droughts, among other things. Extremes in precipitation, both high and low, are rapidly limiting food, fiber, and forest production across the planet (Mohanty et al., 2013). As a result, improving rice’s combined resistance to submergence and drought will significantly enhance rice yield while also preserving water resources and soil quality (Xiong et al., 2019). In order to do this, genotypes containing the submergence resistant gene (Sub1) were assessed in fields under total submergence and severe drought conditions for yield-related characteristics.

In pot experiment highest elongation per day and stem elongation percentage under complete submergence stress was exhibited by KSK-133 and Super Basmati. All the Sub 1 genotypes showed less elongation rate and elongation percentage than local cultivars not having Sub1 gene same results were also observed by Sarkar and Bhattacharjee (2011), Akinwale et al. (2012) and Sarkar et al. (2014), Panda and Sarkar (2012) and Yadav et al. (2018) observed that that survival %age was negatively correlated with plant elongation under submergence. But an extreme reduction in elongation percentage also caused death of plants. So, overall results of present study indicated that extreme reduction in elongation of shoot during stress is not always directly related to the survival of the plants upon de-submergence as KSK-133 showed highest elongation percentage but it also showed good survival percentage comparable to FR-13-A which is considered as submergence tolerant genotype (Sarkar et al., 2014; Sevanthi et al., 2019).

All the genotypes that maintain high chlorophyll contents during submergence and post-submergence period are considered as tolerant genotypes (Singh et al., 2015). So, all the genotypes in present study maintained similar chlorophyll contents under submergence as well as under normal conditions. Winkel et al. (2014) observed that Sub1 was involved in chlorophyll protection during submergence stress. So, all Sub1 genotypes had higher mean values of chlorophyll contents under submergence and control conditions. These results proved that all genotypes under study maintained higher chlorophyll contents after de-submergence and can be categorized as submergence tolerant genotypes.

Complete submergence stress always induces an increase in plant height in rice. So, all the genotypes under study had more plant heights under submergence stress as compare to the normal conditions. Plant height was more in KSK-133 and Super Basmati as compare to Sub1 genotypes. Sultana et al. (2018) observed the increase in plant heights in all genotypes but elogation percentage was less in tolerant genotypes as compared to the susceptible ones. Because, all Sub1 genotypes can survive very well under complete submergence conditions and give good yields. So, in this study submergence stress did not significantly affect the grain, yield, biological yield and harvest index. Same trend was observed by Panda and Sarkar (2012) when they evaluated Swarna and Swarna Sub1 under complete submergence. They observed that the introgression of Sub1 into popular varieties did not have any apparent negative effects on grain yield, yield attributes, and harvest index under controlled field conditions, but considerably enhanced grain yield following submergence. They also observed that the biological yield of the Sub1 genotypes under submergence stress was similar to their biological yield under control conditions. The same trend was also reflected in harvest index for all the genotypes. But in this study, KSK-133 and Super Basmati which did not have Sub1 gene also performed well under stress conditions because of the fact that they might have developed the tolerance mechanism for complete submergence as these local cultivars face flood every year.

Under drought stress the chlorophyll contents were significantly reduced due to severe drought stress as compared to the control conditions. Singh et al. (2018) and Mishra et al. (2018) also observed a severe decline in chlorophyll contents of rice plant under drought stress. Drought stress did not affect the leaf area and number of productive tillers per plant because drought stress was applied at booting stage of the plant. So, plants had already developed their panicle. Mishra and Chaturvedi (2018) also observed a severe decline in panicle lengths of the plants when stress was applied on booting stage. Number of grains per spike and spikelet fertility % and grain yield per plant were severely affected by drought as stress was applied at reproductive stage. Haque et al. (2016) also observed that drought stress at reproductive stage significantly reduced the number of grains per panicle due to which grain yield was decreased by 39%. Akram et al. (2013) also observed the severe drought stress increased the spikelet sterility %. He and Serraj (2012) also reported that terminal drought stress reduced the water potential in leaves and panicles and also reduced the spikelet fertility by 64.6% as compared to control. Swarna Sub1 produced significantly more yield and harvest index under drought stress as compare to the Nagina-22.

Conclusions and Recommendations

Improvement of combined tolerance to submergence and drought would substantially increase rice productivity. Results showed that all Sub1 genotypes performed well not only under submergence stress but also under drought stress. Swarna Sub1 significantly produced more primary branches per panicle yield and harvest index under drought stress as compare to the Nagina-22. Whereas remaining all Sub1 genotypes also showed better performance than drought susceptible check (IR-64) and showed non-significant difference with Nagina-22 for most of the drought tolerance related traits. The results recommended that genotype having Sub1 genes can effectively be grown under rainfed region which are equally prone to floods and drought stress.

Novelty Statement

Previous studies have shown that Sub1 gene not only provides tolerance to submergence stress but also plays a functional role in survival of plants after drought. But all these studies were conducted in laboratory conditions. The present study was conducted to test this hypothesis exclusively in field conditions.

Author’s Contribution

Ifrah Amjad: Conducted the research and wrote-up the manuscript.

Muhammad Nouman Khalid and Rizwan Ahmed Shaikh: Helped in manuscript write-up

Muhammad Kashif: Supervised the study.

Muhammad Noman: Helped in data collection.

Sajid Ali: Proof read the manuscript.

Muhammad Babar and Amna Bibi: Helped in data analysis.

Muhammad Asim Bhutta: Provided technical guidance during research work.

Conflict of interest

The authors have declared no conflict of interest.

References

Afrin, W., M.H. Nafis, M.A. Hossain, M.M. Islam and M.A. Hossain. 2018. Responses of rice (Oryza sativa L.) genotypes to different levels of submergence. C. R. Biol., 341(2): 85-96. https://doi.org/10.1016/j.crvi.2018.01.001

Akhter, M., A. Mahmood, Z. Haider, T. Bibi and R.A.R. Khan. 2019. Developing extra-long grain, early maturing and high yielding basmati rice variety for flood-prone areas of Pakistan. Ann. Adv. Agric. Sci., 3(2): 7-30. https://doi.org/10.22606/as.2019.32001

Akinwale, M.G., B.O. Akinyele, A.C. Odiyi, F. Nwilene, G. Gregoriom and O.E. Oyetunji. 2012. Phenotypic screening of Nigerian rainfed lowland mega rice varieties for submergence tolerance. Proc. Wrl. Congr. Eng., 1: 4-6.

Akram, H., A. Ali, A. Sattar, H. Rehman and A. Bibi. 2013. Impact of water deficit stress on various physiological and agronomic traits of three basmati rice (Oryza sativa L.) cultivars. J. Anim. Plant Sci., 23(5): 1415-1423.

Arif, M., T. Jan, M. Riaz, S. Fahad, M.S. Arif, M.B. Shakoor and F. Rasul. 2019. Advances in rice research for abiotic stress tolerance: Agronomic approaches to improve rice production under abiotic stress. In: Advances in Rice Research for Abiotic Stress Tolerance. Woodhead Publishing. pp. 585-614. https://doi.org/10.1016/B978-0-12-814332-2.00029-0

Azarin, K.V., A.V. Usatov and P. Kostylev. 2017. Molecular breeding of submergence-tolerant rice. Ann. Res. Rev. Biol., 18: 1-10. https://doi.org/10.9734/ARRB/2017/35616

Barik, J., D. Panda, S.K. Mohanty and S.K. Lenka. 2019. Leaf photosynthesis and antioxidant response in selected traditional rice landraces of Jeypore tract of Odisha, India to submergence. Physiol. Mol. Biol. Plants, 25(4): 847-863. https://doi.org/10.1007/s12298-019-00671-7

Bhutta, M.A., S. Munir, M.K. Qureshi, A.N. Shahzad, K. Aslam, H. Manzoor and G. Shabir. 2019. Correlation and path analysis of morphological parameters contributing to yield in rice (Oryza sativa) under drought stress. Pak. J. Bot., 51(1): 73-80. https://doi.org/10.30848/PJB2019-1(28)

Bin-Rahman, A.R. and J. Zhang. 2016. Flood and drought tolerance in rice: opposite but may coexist. Food Energy Secur., 5(2): 76-88. https://doi.org/10.1002/fes3.79

Dixit, S., A. Singh, N. Sandhu, A. Bhandari, P. Vikram and A. Kumar. 2017. Combining drought and submergence tolerance in rice: marker-assisted breeding and QTL combination effects. Mol. Breed, 37(12): 143-154.7. https://doi.org/10.1007/s11032-017-0737-2

Dunnett, C.W., 1955. A multiple comparison procedure for comparing several treatments with a control. J. Am. Stat. Assoc. 50(272): 1096-1121. https://doi.org/10.1080/01621459.1955.10501294

Fukao, T., E. Yeung and J. Bailey-Serres. 2011. The submergence tolerance regulator SUB1A mediates crosstalk between submergence and drought tolerance in rice. Plant Cell, 23(1): 412-427. https://doi.org/10.1105/tpc.110.080325

Haque, K.S., M.A. Karim, M.N. Bari and M.R. Islam. 2016. Genotypic variation in the effect of drought stress on phenology, morphology and yield of aus rice. Int. J. Biosci., 8(6): 73-82. https://doi.org/10.12692/ijb/8.6.73-82

Hazman, M.Y., N. Mohamed and N. Diab. 2019. Drought and salinity alter adaptive molecular response in two genetically unlike Egyptian rice cultivars. Egypt. J. Exp. Biol., 15: 283-294. https://doi.org/10.5455/egyjebb.20190619110050

He, H. and R. Serraj. 2012. Involvement of peduncle elongation, anther dehiscence and spikelet sterility in upland rice response to reproductive-stage drought stress. Environ. Exp. Bot., 75: 120-127. https://doi.org/10.1016/j.envexpbot.2011.09.004

Korres, N., J. Norsworthy, N. Burgos and D. Oosterhuis. 2017. Temperature and drought impacts on rice production: An agronomic perspective regarding short-and long-term adaptation measures. J. Water Resour. Rural Dev., 9: 12-27. https://doi.org/10.1016/j.wrr.2016.10.001

Mahmood, U., H.A. Hussain, S. Hussain, U. Ashraf, A. Khaliq and S. Hussain. 2019. Submergence Stress in Rice: Physiological Disorders, Tolerance Mechanisms, and Management. In: (eds. M. Hasanuzzaman, K. Hakeem, H. Nahar and Alharby) Plant Abiotic Stress Tolerance. Springer, Cham., https://doi.org/10.1007/978-3-030-06118-0_7

Mathan, J., A. Singh and A. Ranjan. 2021. Sucrose transport in response to drought and salt stress involves ABA‐mediated induction of OsSWEET13 and OsSWEET15 in rice. Physiol. Plant., 171(4): 620-637. https://doi.org/10.1111/ppl.13210

Mishra, B. and G. Chaturvedi. 2018. Flowering stage drought stress resistance in upland rice in relation to physiological, biochemical traits and yield. Int. J. Curr. Microbiol. App. Sci., 7(2): 71-82. https://doi.org/10.20546/ijcmas.2018.702.010

Mishra, S.S., P.K. Behera, V. Kumar, S.K. Lenka and D. Panda. 2018. Physiological characterization and allelic diversity of selected drought tolerant traditional rice (Oryza sativa L.) landraces of Koraput, India. Physiol. Mol. Biol. Plants, 24(6): 1035-1046. https://doi.org/10.1007/s12298-018-0606-4

Mohanty, S., R. Wassmann, A. Nelson, P. Moya and S. Jagadish. 2013. Rice and climate change: Significance for food security and vulnerability. In: IRRI discussion paper series no. 49. IRRI. 14

Mori, Y., Y. Kurokawa, M. Koike, A.I. Malik, T.D. Colmer, M. Ashikari, O. Pedersen and K. Nagai. 2019. Diel O2 dynamics in partially and completely submerged deepwater rice: leaf gas films enhance internodal O2 status, influence gene expression and accelerate stem elongation for ‘snorkelling’during submergence. Plant Cell Physiol., 60(5): 973-985. https://doi.org/10.1093/pcp/pcz009

Ostertagova, E. and O. Ostertag. 2013. Methodology and application of one-way ANOVA. Am. J. Mech. Eng., 1: 256-261.

Panda, D. and R.K. Sarkar. 2012. Leaf photosynthetic activity and antioxidant defense associated with Sub1 QTL in rice subjected to submergence and subsequent re-aeration. Rice Sci., 19(2): 108-116. https://doi.org/10.1016/S1672-6308(12)60029-8

Qureshi, R. and M. Ashraf. 2019. Water security issues of agriculture in Pakistan. Pakistan Academy of Sciences, Islamabad, Pakistan. pp. 41.

Sarkar, R., K. Das, D. Panda, J. Reddy, S. Patnaik, B. Patra and D. Singh. 2014. Submergence tolerance in rice: Biophysical constraints, physiological basis and identification of donors. Central Rice Research Institute, Cuttck, India. pp. 36.

Sarkar, R.K. and B. Bhattacharjee. 2011. Rice genotypes with SUB1 QTL differ in submergence tolerance, elongation ability during submergence and re-generation growth at re-emergence. Rice, 5(1): 7. https://doi.org/10.1007/s12284-011-9065-z

Septiningsih, E.M., N. Hidayatun, D.L. Sanchez, Y. Nugraha, J. Carandang, A.M. Pamplona, B.C. Collard, A.M. Ismail and D.J. Mackill. 2015. Accelerating the development of new submergence tolerant rice varieties: the case of Ciherang-Sub1 and PSB Rc18-Sub1. Euphytica, 202(2): 259-268. https://doi.org/10.1007/s10681-014-1287-x

Sevanthi, A.M., C. Prakash and P. Shanmugavadivel 2019. Recent progress in rice varietal development for abiotic stress tolerance. In: (eds. M.F. Hasanuzzaman, N. Kamrun and J.K. Biswas) Advances in Rice Research for Abiotic Stress Tolerance. Woodhead Publishing. https://doi.org/10.1016/B978-0-12-814332-2.00003-4

Singh, A., J.M. Mukul, M. Ram, M. Arya and P. Singh. 2015. Screening and evaluation of rice cultivars for submergence tolerance using SSR markers. Ecoscan, 9(2): 255-259.

Singh, S., S. Prasad, V. Yadav, A. Kumar, B. Jaiswal, A. Kumar, N. Khan and D. Dwivedi. 2018. Effect of drought stress on yield and yield components of rice (Oryza sativa L.) genotypes. Int. J. Curr. Microbiol. Appl. Sci. 7: 2752-2759.

Steel, R.G., J.H. Torrie and D.A. Dickey. 1997. Principles and procedures of statistics: A biometrical approach (3rd ed.). Mc Graw-Hill Inc. New York, USA.

Sultana, T., K.U. Ahamed, N. Naher, M.S. Islam and M.S. Jaman. 2018. Growth and yield response of some rice genotype under different duration of complete submergence. J. Agric. Eco. Res. Int., 15(1): 1-11. https://doi.org/10.9734/JAERI/2018/41754

Swain, P., A. Raman, S. Singh and A. Kumar. 2017. Breeding drought tolerant rice for shallow rainfed ecosystem of eastern India. Field Crops Res., 209: 168-178. https://doi.org/10.1016/j.fcr.2017.05.007

Tiwari, D.N. 2018. A critical review of submergence tolerance breeding beyond Sub 1 gene to mega varieties in the context of climate change. Int. J. Adv. Res. Sci. Eng. Technol., 4(3): 140-148. https://doi.org/10.7324/IJASRE.2018.32647

Tukey, J., 1949. Comparing individual means in the analysis of variance. Biometrics, 5: 99-114. https://doi.org/10.2307/3001913

Upadhyaya, H. and S.K. Panda 2019. Drought stress responses and its management in rice. In: (eds. M.F. Hasanuzzaman, N. Kamrun and J.K. Biswas) Advances in Rice Research for Abiotic Stress Tolerance. Woodhead Publishing. pp. 177-200. https://doi.org/10.1016/B978-0-12-814332-2.00009-5

Winkel, A., O. Pedersen, E. Ella, A.M. Ismail and T.D. Colmer. 2014. Gas film retention and underwater photosynthesis during field submergence of four contrasting rice genotypes. J. Exp. Bot., 65(12): 3225-3233. https://doi.org/10.1093/jxb/eru166

Woolston, C., 2014. Hyperspectral imaging technology combined with genome-wide association study rapidly identifies more genes related to rice quality. Rice Nat., 514(7524): S49-S49. https://doi.org/10.13031/aim.201800489

Xiong, Q., C. Cao, T. Shen, L. Zhong, H. He and X. Chen. 2019. Comprehensive metabolomic and proteomic analysis in biochemical metabolic pathways of rice spikes under drought and submergence stress. BBA-Proteins Proteom., 1867(3): 237-247. https://doi.org/10.1016/j.bbapap.2019.01.001

Yadav, V., S. Prasad, S. Singh and O.P. Verma. 2018. Effect of submergence stress on yield and yield components of various rice (Oryza sativa L.) genotypes with its mapping population. J. Pharmacog. Phytochem., 7(6): 2386-2389.