STUDIES ON HETEROSIS IN PEARL MILLET [PENNISETUM GLAUCUM (L.) R. BR.]

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1 Agric. Sci. Digest., 3 (3) : , 21 AGRICULTURAL RESEARCH COMMUNICATION CENTRE ccjournals.com / indianjournals.com nals.com STUDIES ON HETEROSIS IN PEARL MILLET [PENNISETUM GLAUCUM (L.) R. BR.] K.J. Vagadiya, K.K. Dhedhi, H.J. Joshi, A.S. Bhadelia and H.B. Vekariya Pearl Millet Research Station, Junagadh Agricultural University, Jamnagar-361 6, India ABSTRACT Four cytoplasmic genic male sterile lines were e crossed with 12 diverse pollinators in line x tester design to study the nature and magnitude of heterosis for grain yield and its seven component traits in pearl millet. The extent of heterosis varied in each cross for all the characters studied. The high magnitude of heterosis was observed for grain yield per plant, fodder yield per plant and ear heads weight per plant; medium level of heterosis was exhibited for days to 5 % flowering, days to maturity,, node number per plant and 1-grain weight. While, low amount of heterosis was recorded only for threshing index. Among 48 crosses, 36 and 4 hybrids exhibited significant and positive heterosis over better parent (heterobeltiosis) and standard check (GHB- 719) (standard heterosis), respectively espectively,, for grain yield. The maximum positive heterosis of and 11.3 per cent over better parent ent and standard check, respectively espectively,, was recorded for grain yield per plant. Three most promising hybrids viz., JMSA-272 x J-229, JMSA-273 x H-77/ and ICMA x J-2498 having high heterosis, per se perfor formance coupled with high sca effects involved both or at least one good combiner parents for grain yield. The heterosis in grain yield may be attributed to its component traits, mainly,, ear head weight and dry y fodder yield per plant. Key words : Heterosis, Pearl millet, Line x Tester Pearl millet [Pennisetum glaucum (L.) R. Br.] is the fourth most important cereal crop grown mainly in Rajasthan, U. P., Maharashtra, Gujarat and Haryana in India which account for 95 % of the area under this crop. Pearl millet has an embodiment of unique features like allogamy, protogyny, male sterility, huge genetic variability and remarkable geographic diversity. These characteristics offer great scope for crop improvement through hybridization. Although commercial exploitation of hybrid vigour in pearl millet has resulted in a substantial improvement in the productivity but there is still a need to improve the grain yield to meet to great demand. The magnitude of heterosis provides a basis for genetical diversity and help to choose desirable parents for developing superior heterotic hybrids. Keeping this in view, the present investigation was carried out to understand magnitude of heterosis for grain yield and its components in pearl millet. Four cytoplasmic-genic male sterile lines viz., ICMA-95444, ICMA-98444, JMSA-272, JMSA-273 and 12 diverse restorer lines viz., J-229, J-234, J-245, J-2433, J-2454, J-2467, J-2474, J-2479, J-2483, J-2495, J-2498, H-77/833-2 were included into crossing programme following line x tester mating design during summer-29. A set of 65 genotypes comprising 48 F 1 s along with

2 198 AGRICULTURAL SCIENCE DIGEST fertile counter parts of four male sterile lines, 12 pollinators and one standard check (GHB-719) was evaluated in a randomized block design replicated thrice during Kharif-29 under rainfed conditions at Pearl millet Research Station, Junagadh Agricultural University, Jamnagar (Gujarat), India. Each genotype was grown in a single row of 5. m length each with inter and intra row spacing of 6 x 15 cm. Observations were recorded on ten randomly selected competitive plants for each entry, in each replication for eight characters (Table 1). The heterosis as percentage deviation from the better parent (heterobeltiosis) and the standard check, GHB-719 (standard heterosis) for each character was computed. In the commercial exploitation of hybrid vigour, excess of F 1 over standard check (standard heterosis), is of significance. Hence, in the present investigation, the extent of heterosis over standard check hybrid (GHB-719) for grain yield and seven yield component traits is discussed. Perusal of Table 1 revealed that the degree and direction of heterosis varied considerably for grain yield and its components. Overall, the magnitude of heterotic effects was high for grain yield per plant, fodder yield per plant and ear head weight. Whereas, days to 5 per cent flowering, days to maturity, node number per plant and 1-grain weight recorded moderate heterosis. While, threshing index exhibited the least heterotic value. Pearl millet being grown in erratic conditions of rainfall, the earliness in flowering and maturity is desirable in pearl millet for escaping the drought. Hence, negative heterosis is useful for days to 5 per cent flowering and days to maturity. Out of 48 crosses, seven and nine hybrids had significant and desirable negative heterosis over standard check for days to 5 per cent flowering and days to maturity, respectively. Heterosis over standard check for days to 5 per cent flowering ranged from to per cent; whereas, it ranged from -9.3 to 9.69 per cent for days to maturity, as reported earlier by Bhanderi et al. (27) and Vaghasiya et al., (29). A large number of nodes are considered as a positive character, because the plant height is a desirable character in pearl millet. The extent of standard heterosis for this trait ranged from to per cent which were not significant. However, Chotaliya et al., (29) and Vaghasiya et al., (29) observed heterosis to some extent for this trait. High magnitude of heterobeltiosis has been observed for ear head weight, which is the major yield contributing character. A large number of hybrids (22) exhibiting significant positive better parental heterosis with very high magnitude revealed the prevalence of dominance and over dominance. The range of standard heterosis was from to per cent for this trait. Out of 48 cross combinations studied, only two crosses showed significant positive standard heterosis for ear heads weight per plant. It is interesting to note that the crosses JMSA-272 x J-229 and JMSA-273 x H-77/833-2 occupied first and third rank in standard heterosis, respectively, for ear head weight, also had first and second rank in standard heterosis for grain yield per plant, suggesting the greater contribution of ear heads weight towards grain yield. The findings of Davda et al., (28) and Chotaliya et al., (29) were also similar to that of present study. Test weight being an important yield attributing character, use of parents with high test weight in breeding programme may be most desirable. The range of standard heterosis varied from to 14.4 per cent. The highest standard heterosis for 1-grain weight was observed in cross JMSA-272 x J-2495 (14.4 %) followed by JMSA-273 x J-2467 (1.56 %) and ICMA x J-2479 (9.87 %). Heterosis for test weight in pearl millet was also reported by Singh et al. (24), Chotaliya et al., (29) and Vaghasiya et al., (29). Threshing index is an important character for the indirect measurement of drought resistant in pearl millet. Ten crosses showed positive and significant heterosis over better parent but this character failed to reveal significant standard heterosis in all the crosses studied. The first three top ranking hybrids

3 Vol. 3, No. 3, Table 1: Performance of best per se performing parents and top ranking heterotic crosses associated with range of heterosis, crosses with significant heterosis for various characters in pearl millet Sr. No. Character Best per se performing Range of heterosis (%) Heterosis over better parent (BP) Heterosis over standard check (SC) (GHB-719) parents BP SC Best crosses Heterosis N* Best crosses Heterosis N* 1 Days to J ICMA x J ** 25 JMSA-272 x J ** 5 % J-2498 to to ICMA x J ** JMSA-272 x H-77/ ** flowering J JMSA-272 x H-77/ ** ICMA x H-77/ * 2 Days to J to ICMA x J ** 15 ICMA x J ** maturity J-2498 to 9.69 JMSA-272 x J ** ICMA x J ** ICMA JMSA-272 x H-77/ ** JMSA-272 x H-77/ ** 3 Node J ICMA x J ** 8 JMSA-272 x H-77/ number J-245 to to ICMA x J ** ICMA x J per plant J ICMA x J ** ICMA x J Ear heads J JMSA-272 x J ** 22 JMSA-272 x J ** weight / ICMA to to JMSA-272 x H-77/ ** JMSA-273 x J * Plant (g) J ICMA x J ** JMSA-273 x H-77/ grain ICMA JMSA-272 x J ** 6 JMSA-272 x J weight (g) J-2495 to to 14.4 JMSA-273 x J ** JMSA-273 x J J JMSA-273 x H-77/ ** ICMA x J Threshing H-77/ to JMSA-272 x J ** 1 JMSA-272 x J index (%) J to JMSA-273 x J ** JMSA-272 x J J ICMA x J ** JMSA-272 x J Fodder yield J JMSA-272 x J ** 15 JMSA-273 x J ** per plant (g) J-245 to to JMSA-272 x J ** JMSA-273 x J ** JMSA ICMA x J ** ICMA x J ** 8 Grain yield J ICMA x J ** 36 JMSA-272 x J ** per plant (g) JMSA-273 to to JMSA-272 x J ** JMSA-273 x H-77/ ** J JMSA-272 x H-77/ ** ICMA x J ** *N =Number of crosses showing significant desirable heterosis

4 2 AGRICULTURAL SCIENCE DIGEST Table 2: Best heterotic crosses with per se performance, gca and sca effects for grain yield per plant and significant desirable heterobeltiosis for other traits in pearl millet. Crosses Grain yield/ Heterosis (%) over sca gca effects Traits with Plant(g) BP SC of parents significant desirable Female Male heterobeltiosis JMSA-272 x J ** 11.3** 3.74** Poor Good DF, EW, DM, FY, GY. JMSA-273 x H-77/ ** 9.8** 5.54** Good Good DF, EW, TW, GY. ICMA x J ** 8.99** 7.66** Poor Good EW, FY, GY. JMSA-273 x J ** 6.21* 8.39** Good Poor DF, EW, DM, GY. ICMA x J ** 5.73* 2.69** Poor Good DF, EW, DM, FY, GY. Significant at 5% and 1%, respectively. DF= Days to 5 % flowering, DM= Days to maturity, EW = Ear heads weight per *,** plant, TW = 1 grain weight, FY =Dry fodder yield per plant, GY=Grain yield/plant. viz., JMSA-272 x J-2498, JMSA-272 x J-2495 and JMSA-272 x J-2467 had common female parent, JMSA-272, indicating greater contribution of this female towards the threshing index. Heterosis for threshing index was also observed by Bhanderi et al. (27). Paramount of heterosis has been observed in fodder yield, which is an important component of pearl millet being a dual-purpose crop. The cross JMSA-273 x J-245 (48.9 %) recorded the maximum standard heterosis for higher dry fodder yield followed by JMSA-273 x J-2479 (42.2 %) and ICMA x J-2454 (39.72 %). Among 48 crosses, 15 and 13 displayed significant and positive heterosis over better parent and standard check, respectively, for this trait, suggesting the greater role of fodder yield in the expression of grain yield. This outcome is in accordance with that of Chotaliya et al., (29) who reported association between grain yield and bio-mass. Grain yield is of economic importance for which considerable degree of heterosis was registered in a number of crosses. Among the crosses studied, 36 hybrids exhibited positive heterosis over better parent (-25.9 to 15.7 %) and four hybrids manifested significant positive standard heterosis ( to 11.3 %). Interestingly, the magnitude in positive direction was too high particularly in heterobeltiosis. Perusal of Table 1 also revealed the number of crosses displaying heterobeltiosis in various yield-attributing characters were small, whereas, the number of crosses showing heterobeltiosis in grain yield were many (36).This result indicated that the favourable combination of yield contributing characters resulted in a higher proportion of cross combinations showing significant positive heterobeltiosis. Among the 48 crosses studied, five hybrids were identified as most promising for grain yield, based on magnitude of heterosis over standard check (GHB-719) (Table 2). The highest per se performing hybrid JMSA-272 x J-229 involving poor x good general combining parents attained first rank in standard heterosis, coupled with high heterobeltiosis and sca effect. This cross also occupied first rank in ear head weight for standard heterosis revealing significant contributions of this character towards the increasing grain yield. Similarly, the cross combination ICMA x J-2498 involving poor x good combiners which ranked first in heterobeltiosis, placed in third rank for its per se performance. This cross also ranked third in heterobeltiosis for dry fodder yield per plant, suggesting the greater role of this trait towards the grain yield. While hybrid JMSA-273 x H-77/833-2 involving good x good combiner parents secured second rank in per se performance, placed ninth rank in sca with high heterobeltiosis for grain yield. All the five most superior standard heterotic hybrids identified for grain yield exhibited significant

5 Vol. 3, No. 3, heterobeltiosis in desired direction for ear heads weight per plant and grain yield per plant, while four crosses for days to 5 per cent flowering, three each for days to maturity and dry fodder yield per plant and one for 1-grain weight. The results indicated that the high heterotic effects of grain yield per plant were mainly due to the contribution by ear heads weight per plant and dry fodder yield per plant. Present findings are akin with earlier results of Yadav et al. (2), Bhanderi et al. (27), Davda et al., (28), Chotaliya et al., (29) and Vaghasiya et al., (29). Therefore, in the present study, three top ranking hybrids for grain yield viz., JMSA- 272 x J-229, JMSA-273 x H-77/833-2 and ICMA x J-2498 with high per se performance had a high heterotic effect along with high sca and also exhibited high heterobeltiosis for various important yield components. Thus, it was suggested to evaluate these three hybrids further under multilocation trials along with the standard hybrids for release as high yielding hybrids in pearl millet. REFERENCES Bhanderi, S. H. et al. (27). Int. J. of Bioscience Reporter, 5: Chotaliya, J. M. et al. (29). Internat. J. Agric. Sci., 5: Davda, B. K. et al. (28). Internat. J. Agric. Sci., 4: Singh, A. K. et al. (24). Agric. Sci. Digest., 24: Vaghasiya,V.D. et al. (29). Agric. Sci. Digest., 29: Yadav, O.P. et al (2). Euphytica, 112: