Heterosis studies in CGMS based hybrids of pearl millet Pennisetum glaucum (L.) R. BR.

Introduction

Pearl millet (Pennisetum glaucum (L.) R. Br.) is a key member of the Poaceae (Gramineae) family and the Pennisetum genus. Commonly known as bajra, bajri, cattail millet, spiked millet, and bulrush millet, this crop is highly cross-pollinated and features protogynous flowering with wind-borne pollination. These traits facilitate hybrid development and the commercial benefits of heterosis. In India, pearl millet is a major staple food, ranking fourth in acreage after rice, wheat, and sorghum, and it is the sixth most important cereal globally (Acharya et al. 2017) [1] . Believed to have originated in tropical Western Africa around 4000 years ago, pearl millet is diploid, with a chromosome number of 2n=2x=14. Exploitation of hybrid vigor is considered to be one of the outstanding achievements in this crop. Cross pollinated nature and availability of male sterile lines in crop had made of its feasible to exploit hybrid vigor on commercial scale. Therefore, to identify better heterotic response for grain yield and its components characters are of paramount importance (Patel et al. (2016) [20] .

Materials and Methods

The experimental material comprised of nine CGMS (Female) lines viz., JMSA 1 20208, JMSA 5 20211, JMSA 4 20215, JMSA 4 20221, JMSA 4 20223, ICMA 1 17555, ICMA 4 18222, ICMA 1 93333, ICMA 1 97111; five restorer (male) lines of pearl millet viz., J-2296, J-2480, J-2571, J-2576, J-2604 and their 45 F 1 s hybrids developed by line × tester design and one standard check hybrid (GHB 1129) (Table 1). They were evaluated in randomized block design (RBD) with three replications at Main Pearl Millet Research Station, J.A.U., Jamnagar during kharif 2024. Row to row and plant to plant spacing was 60 cm × 15 cm. To produce a better crop, the region's recommended agronomic practices were followed. The observations were recorded on five randomly selected plants expect the plot basis from parents and crosses for 12 characters viz., days to 50% flowering, days to maturity, plant height, number of effective tillers per plant, earhead length, earhead diameter, dry earhead weight per plant, 1000-grain weight, dry fodder yield per plant, grain yield per plant, threshing index and harvest index. Mean data were used for statistical analysis. The variance analysis for each character was performed using the method described by Panse and Sukhatme (1995). Heterosis was estimated in term of two parameters, i.e. heterobeltiosis (heterosis over better parental value) as suggested by Fonseca and Patterson (1968) and standard heterosis (heterosis over standard check) as suggested by Meredith and Bridge (1972) [18,10,15] .

Results and Discussion

The analysis of variance showed highly significant differences among the genotypes for all the traits under studied. Thus, the results quantified the considerable amount of genetic diversity exist among genotypes for the different traits under study. The genotypic variance was further partitioned into different source of variances. It is cleared that the variance due to parents and crosses was significant for all the 12 characters under studied except day to maturity due to crosses. However, mean squares due to parents vs crosses were found significant for all the characters under studied except number of effective tillers per plant and earhead diameter, indicating the significant difference between the parents and crosses for these important traits. Further, partitioning of mean squares due to parents into lines, testers and lines vs testers revealed that the mean squares due to lines were significant for all the characters. Mean squares due to testers were found significant for all the characters under studied except for threshing index. The mean squares due to lines vs testers were significant for all characters except for plant height, dry earhead weight per plant, 1000-grain weight and dry fodder yield per plant, indicating the significant difference between male and female parents for these traits. Magnitude of variability was higher with lines for earhead length, earhead diameter, 1000-grain weight, threshing index and harvest index in comparison to testers. This indicated that the more contribution of lines in total variance for these characters, while the magnitude of variability was higher with testers for the rest of the traits under studied to the total variance (Table 2). Similar result observed by Moghariya et al. (2024) [16] for days to 50% flowering, days to maturity, number of effective tillers per plant, earhead length, dry earhead weight per plant, 1000-grain weight, grain yield per plant, threshing index and harvest index. A number of crosses depicted significant heterosis over better parent and standard check in favourable direction for grain yield per plant (36, 5), days to 50 per cent flowering (41, 0), days to maturity (35, 0), plant height (42, 15), number of effective tillers per plant (11, 3), earhead length (23, 38), earhead diameter (11, 8), dry earhead weight per plant (35, 19), 1000-grain weight (21, 15), dry fodder yield per plant (35, 20), threshing index (14, 1) and harvest index (10, 3), respectively(Table 3). Performance of crosses in respect of heterosis over better parent and standard check (GHB 1129) revealed that the high magnitudes of heterobeltiosis in desirable direction was found for grain yield per plant, plant height, number of effective tillers per plant, earhead length, earhead diameter, dry earhead weight per plant, 1000-grain weight, dry fodder yield per plant, threshing index and harvest index. The moderate magnitude of heterosis over better parent was recorded for days to 50% flowering and days to maturity. Similar observations were also made by pethani et al. [24,22,4,21] . Earliness is desirable character in pearl millet and days to 50% flowering is component which effects on earliness. The range of heterobeltiosis for days to 50% flowering was -22.40% (ICMA1 17555 × J-2571) to 0.00% (JMSA4 20215 × J-2571). The standard heterosis ranged from -4.23% (JMSA1 20208 × J-2480) to 12.68% (ICMA1 17555 × J-2604) (Table 3). Similar results for heterobeltiosis and standard heterosis in negative desirable directions were [25,19] . The range of heterobeltiosis for days to maturity was -16.16% (ICMA4 18222 × J-2296) to 0.98% (JMSA4 20215 × J-2571). The range of standard heterosis for days to maturity was between -2.52% (JMSA1 20208 × J-2480) to 7.48% (ICMA1 17555 × J-2604). Similar findings were reported by), Davda et [9,4,28,23] . Plant height is regarded as a favourable character due to the important role of the stem in supplementing assimilates during grain development. The range of heterobeltiosis, for plant height was -0.55% (ICMA1 97111 × J-2604) to 68.11% (ICMA1 17555 × J-2480). The range of standard heterosis for plant height varied from -7.11% (JMSA1 20208 × J-2480) to 26.46% (JMSA4 20221 × J-2604). These results are agreed with the results obtained by Suryawanshi et [4,2,29] . The heterosis over better parent for earhead diameter laid between -32.00% (JMSA4 20223 × J-2296) to 37.31% (JMSA4 20223 × J-2480). The estimates of standard heterosis ranged between -18.18% (JMSA5 20211 × J-2576) and 44.16% (JMSA4 20215 × J-2571) for earhead diameter. The results were the same as reported by Salagarkar [26,17,8] [2,13] . Considering heterosis over better parent, the variation for 1000-grain weight was from -28.99% (JMSA5 20211 × J-2576) to 57.55% (JMSA5 20211 × J-2296). Estimations of standard heterosis for 1000-grain weight ranged from -17.49% (JMSA5 20211 × J-2576) to 48.66% (ICMA1 17555 × J-2576). Positive estimation of heterosis in this trait was also reported by Sharma et [27,16] . For dry fodder yield per plant, the estimates of heterobeltiosis ranged from - 13 [3,16,7] . Range of heterosis over better parent for grain yield per plant was -34.69% (ICMA4 18222 × J-2571) to 141.48% (ICMA1 17555 × J-2576). The minimum and the maximum values of heterosis over standard check were -41.36% (ICMA4 18222 × J-2571) and 58.64% (JMSA4 20215 × J-2604). The highest positive and significant standard heterosis showed by the cross JMSA4 20215 × J-2604 (58.64%) followed by JMSA4 20215 × J-2576 (29.83%) and JMSA4 20215 × J-2571 (26.10%) for this trait. These results are in conformation to the findings of), Athoni et [3,13,27,16,7] . The values of heterobeltiosis for threshing index ranged from -55.14% (ICMA4 18222 × J-2571) to 56.65% (ICMA1 97111 × J-2576). The range of standard heterosis for threshing index varied between -50.23% (ICMA4 18222 × J-2571) to 17.78% (JMSA1 20208 × J-2480). The significant results in a positive direction for threshing index were reported by Athoni et [19,11,16,7] . The superior cross JMSA4 20215 × J-2604 was also exhibited significant standard heterosis in desired direction for the characters, viz., plant height, earhead length, dry earhead weight per plant and dry fodder yield per plant suggesting the greater role of these traits towards the grain yield. This cross had also registered significant heterobeltiosis in desirable direction for days to 50 per cent flowering, plant height, number of effective tillers per plant, earhead length, dry earhead weight per plant, 1000-grain weight, dry fodder yield per plant, threshing index and harvest index (Table 4). The second highest heterotic cross JMSA4 20215 × J-2576 was recorded significant and positive heterosis over standard check for plant height, earhead length, dry earhead weight per plant, 1000-grain weight and dry fodder yield per plant. This cross had also exhibited significant heterobeltiosis in desired direction for plant height, number of effective tillers per plant, earhead length, dry earhead weight per plant, 1000grain weight, dry fodder yield per plant, threshing index and harvest index (Table 4). The second highest heterotic cross JMSA4 20215 × J-2576 was recorded significant and positive heterosis over standard check for plant height, earhead length, dry earhead weight per plant, 1000-grain weight and dry fodder yield per plant. This cross had also exhibited significant heterobeltiosis in desired direction for plant height, number of effective tillers per plant, earhead length, dry earhead weight per plant, 1000grain weight, dry fodder yield per plant, threshing index and harvest index (Table 4). On the other hand, the fourth highest heterotic cross ICMA4 18222 × J-2296 had significant standard heterosis in desirable for earhead length, earhead diameter, dry earhead weight per plant and harvest index. The fourth highest heterotic cross, ICMA4 18222 × J-2296 was also recorded significant heterosis over better parent in desirable direction for days to 50 per cent flowering, days to maturity, plant height, earhead length, dry earhead weight per plant and dry fodder yield per plant (Table 4). Similarly, the fifth highest heterotic cross ICMA1 17555 × J-2604 was manifested significant standard heterosis in desirable direction to plant height, earhead length, dry earhead weight per plant and dry fodder yield per plant. The same cross ICMA1 17555 × J-2604 had also noticed significant and positive heterobeltiosis for days to 50% flowering, days to maturity, plant height, dry earhead weight per plant, dry fodder yield per plant, threshing index and harvest index (Table 4). It is interesting to note that the high heterotic crosses for grain yield did not show high heterosis for all the yield component traits (Table 4). But it was fact from present investigation that the significant and positive heterosis for grain yield was associated with significantly desirable heterosis for two or more yield attributing traits. Similar cumulative heterotic effect of two or more yield components on grain yield of pearl millet was also reported earlier by Jethva et (2024) [12,4,20,1,14,25,21,3,16] .

Conclusion

From ongoing discussion, it could be concluded that the best two promising crosses viz., JMSA4 20215 × J-2604 and ICMA4 18222 × J-2296 exhibited high per se performance, significant and positive heterobeltiosis as well as standard heterosis in desired direction for grain yield per plant and some components traits. Therefore, these two best crosses could be further evaluated over years and locations to exploit for commercial cultivation through heterosis breeding or utilized in future breeding programme to obtain desirable transgressive segregants and to identify high yielding superior inbreds.

References

1. Acharya ZR, Khanapara MD, Chaudhari VB, Dobaria JD. Exploitation of heterosis in pearl millet [Pennisetum glaucum (L.) R. Br.] for yield and its component traits by using male sterile lines. International Journal of Current Microbiology and Applied Sciences. 2017;6(12):750759.
2. Aswini MS, Ganesan KN, Ezhilarasi T, Sivakumar SD. Combining ability and heterosis studies in fodder pearl millet [Pennisetum glaucum (L.) R. Br.]. Electronic Journal of Plant Breeding. 2021;12(3):1011-1021.
3. Athoni BK, Biradar BD, Patil SS, Patil PV, Guggari AK. Genetic studies for heterosis for grain yield and yield components using diverse male sterile lines in pearl millet [Pennisetum glaucum (L.) R. Br.]. Journal of Agriculture Research and Technology. 2022;47(1):8895.
4. Bachkar RM, Pole SP, Patil SN. Heterosis for grain yield and its components in pearl millet (Pennisetum glaucum L.). Indian Journal of Dryland Agricultural Research and Development. 2014;29(1):40-44.
5. Badhe PL, Patil HT, Borole DN, Thakare SM. Heterosis for yield and morpho-nutritional traits in pearl millet [Pennisetum glaucum (L.) R. Br.]. Electronic Journal of Plant Breeding. 2018;9(2):759-762.
6. Bhasker K, Shashibhushan D, Murali Krishna K, Bhave MHV. Studies on heterosis for grain yield and its contributing characters in hybrids of pearl millet [Pennisetum glaucum (L.) R. Br.]. International Journal of Plant and Soil Science. 2017;18(5):1-6.
7. Bhatiya BD, Polara AM, Kandoriya DV, Savaliya JJ, Moghariya AA, Gohil HB, et al. Exploitation of heterosis for grain yield and yield components in pearl millet [Pennisetum glaucum (L.) R. Br.] using diverse male sterile lines. Plant Archives. 2025;25(Suppl 1):453462.
8. Chittora K, Patel JA. Estimation of heterosis for grain yield and yield components in pearl millet [Pennisetum glaucum (L.) R. Br.]. International Journal of Current Microbiology and Applied Sciences. 2017;6(3):412-418.
9. Davda BK, Dhedhi KK, Dangaria CJ. Evaluation of heterosis in pearl millet [Pennisetum glaucum (L.) R. Br.] under rainfed condition. International Journal of Plant Sciences. 2012;7(1):74-78.
10. Fonseca S, Patterson F. Hybrid vigour in a seven-parent diallel cross in common winter wheat (Triticum aestivum L.). Crop Science. 1968;8(1):85-88.
11. Galani SN, Madariya RB, Parmar SK, Sorathiya JS. Study of heterosis in F1 and F2 generations of pearl millet [Pennisetum glaucum (L.) R. Br.]. The Pharma Innovation Journal. 2022;11(9):1621-1622.
12. Jethva AS, Raval L, Madariya RB, Mehta DR, Mandavia C. Heterosis for grain yield and its related characters in pearl millet. Electronic Journal of Plant Breeding. 2012;3(3):848-852.
13. Kapildev, Athoni BK, Soregaon CD, Hosamani J. Heterosis studies for yield and yield components using biofortified restorers on A1 CMS lines in pearl millet [Pennisetum glaucum (L.) R. Br.]. Journal of Farm Sciences. 2023;36(4):333-337.
14. Ladumor VL, Mungra KD, Parmar SK. Heterosis for grain yield component in pearl millet [Pennisetum glaucum (L.) R. Br.]. Trends in Biosciences. 2018;11(27):3473-3477.
15. Meredith WR, Bridge RR. Heterosis and gene action in cotton (Gossypium hirsutum L.). Crop Science. 1972;12(3):304-310.
16. R. Br.] hybrids involving diverse CGMS lines and restorers. Asian Research Journal of Agriculture. 2024;17(4):1045-1052.
17. Pallavi M, Radha Krishna KV, Reddy PS, Ratnavathi CV, Sujatha P, Sriram A. Heterosis for grain yield, rancidity and associated characters in pearl millet (Pennisetum glaucum L.). The Journal of Research PJTSAU. 2020;48(1-2):28-38.
18. Panse VG, Sukhatme PV. Statistical methods for agricultural workers. 4th rev ed. New Delhi: ICAR; 1995.
19. Pareek A, Sharma LD, Singh J, Singh RV, Sharma V. Heterosis studies for grain yield and its contributing traits in pearl millet [Pennisetum glaucum (L.) R. Br.] under different sowing conditions. International Journal of Current Microbiology and Applied Sciences. 2020;9(7):520-528.
20. Patel BC, Doshi JS, Patel JA. Heterosis for grain yield components in pearl millet [Pennisetum glaucum (L.) R. Br.]. Innovare Journal of Agricultural Science. 2016;4(3):1-3.
21. Patel KN, Dhedhi KK, Bamji RC. Heterosis for grain yield and its component traits in pearl millet [Pennisetum glaucum (L.) R. Br.] using line × tester analysis. International Journal of Chemical Studies. 2019;7(5):1406-1409.
22. Patil CM, Aher RP, Anarase SS, Suryawansi NV. Heterosis for grain yield and its components in pearl millet. Journal of Maharashtra Agricultural University. 2008;33(1):4-6.
23. Pawar VY, Kute NS, Patil HT, Awari VR, Gavali RK, Deshmukh GP. Heterosis for earliness in pearl millet [Pennisetum glaucum (L.) R. Br.]. BIOINFOLET -A Quarterly Journal of Life Sciences. 2015;12(3B):696706.
24. Pethani KV, Atara SD, Monpara BA. Heterosis and combining ability for plant and seed characters in pearl millet. National Journal of Plant Improvement. 2004;6(2):115-118.
25. R. Br.]. Indian Journal of Agricultural Research. 2019;53(5):572-577.
26. Salagarkar S, Wali MC. Heterosis for yield and yieldrelated components using diverse restorer lines in pearl millet [Pennisetum glaucum (L.) R. Br.]. Journal of Farm Sciences. 2016;29(4):436-438.
27. Sharma SK, Solanki KL, Gupta PC. Heterosis for grain yield and its components in pearl millet [Pennisetum glaucum (L.) R. Br.]. Annals of Arid Zone. 2023;62(2):141-145.
28. Singh B, Sharma KC, Mittal GK, Meena HK. Heterosis for grain yield and its component traits in pearl millet in different environments. International Journal of Tropical Agriculture. 2015;33(1):47-51.
29. Sumathi P, Revathi S. Heterosis and variability studies for yield and yield component traits in pearl millet [Pennisetum glaucum (L.) R. Br.]. Electronic Journal of Plant Breeding. 2017;8(2):528-533.
30. Suryawanshi MB, Deore GN, Gavali RK, Karvar SH, Shinde GC, Langi AM, Banik M. Heterosis analysis for grain yield components in pearl millet [Pennisetum glaucum (L.) R. Br.]. Journal of Pharmacognosy and Phytochemistry. 2021;10(1):1878-1881.