Innovative Agriculture Research Initiative (iagri) MAJOR ADVISOR: Dr. (Mrs.) S. K. Thind, Professor (Head cum) Department of Botany, Punjab Agricultural University Ludhiana, India. MINOR ADVISORS: Dr. G. S. Mangat, Senior Rice Breeder, Department of Plant Breeding and Genetics, Punjab Agricultural University Ludhiana, India. Dr. (Mrs.) Nirmaljit Kaur, Senior Botanist, Department of Botany, Punjab Agricultural University Ludhiana, India. PREPARED BY; HILALI SALEH HILALI
Physiological studies on rice (Oryza sativa L.) Under high temperature stress OBJECTIVES To determine the physiological basis of high temperature stress on growth and developmental stages of the selected genotypes of rice. To study the effects of high temperature on yield performance of selected rice genotypes.
EXPERIMENTAL MATERIALS Twenty genotypes of rice (O. sativa L.) were used Obtained from Department of Plant Breeding and Genetics, Punjab Agricultural University, PAU Ludhiana. Three replications Randomized Complete Block Design (RBD) Data were analyzed using SAS; ANOVA and Pearson correlation
Table 1: Designation Genotype HT1 HT2 HT5 HT6 HT9 HT10 HT11 Designation Balilla Cuiabana Ganja Rangwala Ganjay IR6 IR61250 3B 7 1 2 IR65192 4B 17 3 Genotype HT12 HT13 HT14 HT15 HT16 HT23 HT24 HT25 Designation 1R2006 P12 12 2 2 IR2307 247 2 2 3 IR28 IR50 IR72 Sadri Sahel 108 Tak Ratia Genotype PR121 PR122 PR123 PB1121 PPB1509 Designation Punjab rice 121 Punjab rice 122 Punjab rice 123 Punjab Basmati 1121 Punjab Pusa Basmati 1509
Experimental conditions Stress growing environment (summer season) Sown in nursery on 06 th March 2014 transplanted on 03 rd and 04 th April 2014. Normal growing environment (winter season) Sown on 21 st May transplanted on 21 st June 2014.
EXPERIMENTAL RESULTS Number of stomata ANOVA showed that the number of stomata in lower and upper epidermis along with their ratio were significantly (P< 0.05) affected by growing environment, genotype and interaction between genotype and growing environment. Except, the stomatal ratio was not significantly (P>0.05) affected by growing environment (Table 2)
Table 2: Average number of stomata with their stomatal ratio Normal growing environment Stress growing environment Genotypes Upper Ep Lower Ep Ratio (L/U Ep) Upper Ep Lower Ep Ratio (L/U Ep) Balilla 16 31 2 22 36 4 Cuiabana 13 27 2 19 32 2 Ganja Rangwala 17 46 3 13 39 3 Ganjay 11 17 2 12 15 2 IR6 18 26 2 19 37 2 IR61250 16 26 2 18 28 2 IR65192 19 20 1 31 35 1 IR2006 14 40 3 16 56 4 IR2307 18 48 3 45 71 2 IR28 16 28 2 17 45 3 IR50 10 31 5 11 21 2 IR72 23 52 2 21 25 1 Sadri 30 45 2 19 51 3 Sahel 108 23 31 1 19 29 2 Tak Ratia 16 25 2 14 24 2 PR 121 13 35 3 18 28 2 PR 122 16 23 2 17 26 2 PR 123 17 30 2 19 77 4 PB1121 19 27 1 13 45 5 PPB1509 10 53 5 21 66 3 LSD at 5% 6.5905 18.925 1.6117 11.569 22.107 2.6694
Discussion for stomata The number of stomata in both sides of leaves increased significantly (P< 0.05) under stress growing environment But the stomatal ratio was not affected by growing environment. The number increased in the same fold for both sides of leaves.
Discussion cont Pearson correlation analysis revealed no significant correlation between number of stomata with yields for both growing environments Some genotypes had high number of stomata with high yield while others had low number of stomata with high yield. Stomata is a complex parameter, more researches are required.
Table 3: Plant height (PH), Flag leaf angle (FLA) and Peduncle length (Pd L) Normal growing environment Stress growing environment Genotype PH (cm) FLA Pd L (cm) PH (cm) FLA Pd L (cm) Balilla 111.3 14 3.8 76.1 15 1.5 Cuiabana 134.1 28 5.2 107.2 45 3.2 Ganja Rangwala 130.3 23 6.6 134.7 32 4.1 Ganjay 123.9 19 4.6 101.7 19 3.8 IR6 115.3 47 3.8 102.2 47 0.7 IR61250 113.1 14 4.3 103.3 15 6.0 IR65192 100.0 10 4.6 95.0 11 4.5 IR2006 99.5 40 4.5 87.7 47 3.6 IR2307 100.1 17 3.7 77.7 17 1.2 IR28 105.7 21 4.9 80.0 23 3.1 IR50 126.5 17 6.4 94.3 18 4.6 IR72 107.1 27 4.2 86.1 28 2.8 Sadri 162.2 28 8.1 131.5 53 1.9 Sahel 108 112.5 18 2.5 93.2 25 3.6 Tak Ratia 135.1 28 5.2 142.1 28 3.9 PR 121 99.5 11 5.4 82.7 25 0.7 PR 122 108.3 11 5.5 103.2 11 2.7 PR 123 105.6 13 2.3 90.4 17 1.6 PB1121 125.5 11 5.1 111.5 29 3.4 PPB1509 110.0 26 5.2 76.4 48 2.0 LSD at 5% 11.189 5.0369 Graduate Research 1.6933 Workshop 5.8487 11.377 1.5446
Experimental Results for PH, FLA and Pd L ANOVA showed that PH, FLA and Pd L for selected rice genotypes were significantly (P< 0.05) affected by growing environment, genotype as well as an interaction between genotypes and growing environment (Table 3) PH and Pd L were significantly (P< 0.05) reduced under stress growing environment but FLA increased significantly. Correlation analysis found significant negative correlation between PH (r= 0.53**), FLA (r= 0.22**), and Pd L (r= 0.27**) with grain yield
Discussion for PH, FLA and Pd L Genotype PR121 had lowest PH and Pd L under stress, which negatively correlated with its highest yield It can provide germplasm resource to produce high yield dwarf and low Pd L variety under high temperature. Genotype Tak Ratia had highest PH which negatively correlated with its very low yield under stress environment.
Discussion cont. Genotype PR122 recorded lowest flag leaf angle which negatively correlated with its high grain yield It offers best option to exploit germplasm for FLA under stress environment.
Table 4: % Pollen sterility, % Spikelet sterility and Yield (Kg/ha) Normal growing environment Stress growing environment Genotype % Yield % Pollen %Spikelet Yield % Pollen %Spikelet Yield decline Sterility Sterility (Kg/ha) Sterility Sterility (Kg/ha) Balilla 0 20.1 8069.4 3 33.3 6465.2 19.9 Cuiabana 0 15.5 7194.4 0 37.7 6420.7 10.8 Ganja Rangwala 1.7 14 7027.8 1.8 16.2 4477.0 36.3 Ganjay 0 14.8 11671.3 2.3 22.4 9063.7 22.3 IR6 0 12.7 9634.3 5.8 45.6 9614.8 0.2 IR61250 0 24.1 9708.3 9.2 32.1 7706.7 20.6 IR65192 0 29.6 5333.3 1.8 29.6 4634.1 13.1 IR2006 0 17.2 7726.9 4.2 23.3 7191.1 6.9 IR2307 3.9 11.6 8468.1 22.9 21.6 8032.4 5.1 IR28 3 16.5 8203.7 5.5 45.3 6571.9 19.9 IR50 0 26.6 9083.3 1.4 61.8 6275.6 30.9 IR72 3.5 34.1 8157.4 6.1 38.8 7691.9 5.7 Sadri 0 15.1 6120.4 8.6 39.1 2160.0 64.7 Sahel 108 1.2 34.7 6479.2 3.8 35.9 5277.0 18.6 Tak Ratia 26 18.6 4092.6 58.8 73.7 394.1 90.4 PR 121 9.6 10.8 11180.6 10.6 17.8 10269.6 8.1 PR 122 1.3 8.8 9445.9 4 21.4 9342.6 1.1 PR 123 2.9 9 10888.9 4.4 27.3 9662.2 11.3 PB1121 6.7 17.8 6638.9 8.7 100 0.0 100.0 PPB1509 1.2 20.9 7041.7 10 49.9 6100.7 13.4 LSD at 5% 2.925 6.213 2387.3 2.701 24.546 2544.5 157.2
Experimental Results ANOVA showed that % pollen and spikelet sterility were significantly (P< 0.05) affected by growing environment, genotypes as well as an interaction between genotype and growing environment(table 4) Rice genotypes had significantly (P< 0.05) higher pollen and spikelet sterility but lower yield (kg/ha) under stress environment. Pearson Correlation analysis revealed the following; significant positive correlation between pollen sterility with spikelets sterility (r=0.31**). significant negative correlation between pollen (r= 0.39**), and spikelet sterility (r= 0.53**) with yield.
Discussion for % Pollen sterility, % Spikelet sterility and Yield (Kg/ha) Genotype Tak Ratia had significant highest % pollen sterility and higher (73.7%) % spikelet sterility hence very low yield. Genotype PB1121 showed 100% spikelet sterility with no grain yield (kg/ha) Genotype PR121 had the lowest value of % spikelets sterility hence highest yield (kg/ha) Other genotypes; PR123, IR61250, IR6, PR122, IR2307 and IR2006 also maintained higher yields than other genotypes in both growing environments.
Fig 1: Yield of rice genotypes under normal and stress growing environment 14000 12000 10000 Yield (kg/ha) 8000 6000 4000 normal stress 2000 0 Genotypes
Conclusion Overall; Genotypes PR121, PR122, IR6 and Ganjay appeared to perform better in many traits under stress environment among all selected genotypes They offer best option for high temperature climate While genotypes Tak Ratia and PB1121 were poorly adapted to high temperature.