Keragaman Genetik dan Penampilan Jagung Hibrida Silang Puncak pada Kondisi Cekaman Kekeringan

Abstract

Maize breeding population with a wide genetic diversity is required to develop superior drought tolerant varieties. The objective of this research was to obtain information on genetic diversity, heritability value and grain yield performance, yield components and agronomic traits of maize genotypes derived from top cross under severe drought stress. One hundred and fifty maize genotypes derived from top cross and four hybrids maize as check varieties, were tested in Probolinggo, East Java, and Gowa, South Sulawesi during dry season of 2013. Factorial randomized block design with two replications was used in thisexperiment. Each hybrid was grown in two rows of 5 m length plot, one plant per hill spaced 70 cm between rows and 20 cm within row. Results showed that top cross hybrids had significantly different responses to drought stress. Broad sense heritability, value of silking, number grain-rows per ear, and shelling percentage were high. Heritability estimates for of anthesis, anthesis-silking interval, plant height, ear height, weight and ear performance, ear length, 1000 seeds weight and grain each yield were intermediate. The 20 best hybrids based on the highest grain yield, consisted of 17 genotypes with good combining ability with P21, 2 genotypes had good combining ability with Bima 11 and only one genotype had good combining ability with both the top cross parents, (P21 and Bima 11). Grain yield of 20 top cross hybrids in Probolinggo ranged from 4.8 t/ha to 6.7 t/ha significantly higher than that of tester varieties, while yields in Gowa ranged from 4.5 t/ha-6.7 t/ha. Only 4 tested hybrids significantly outyielded the four tester varieties. For the purpose of further selection, determining of the best S1 genotype should be done per location to overcome large environmental effects.

Estimation of Genetic Variance and Heritability of F2 Populations of Corn Plants in Dry Land

“…Several researchers have studied heritability in maize. Wannows, et al (2010);Shahrokhi, et al (2013); Azrai, et al (2016); Kandel et al (2018); Lubis, et al (2014) found that the character of ASI (Anthesis Silk Interval), cob dry weight, seed dry weight, and cob weight/plot had broad genetic diversity values, followed by high heritability. Traits that have wide genetic diversity and high heritability can be selected directly.…”

Genetic diversity and gain quantitative characters of maize from index-based selection at two dry lands in Lombok, Indonesia

“…Narrow genetic diversity indicates that subsequent selection for this trait will not be effective (Rachman et al 2022). Azrai et al (2016) reported the same result that the genetic diversity of harvest cob weight was narrow with a genetic diversity value of 0.11 and a CGD value of 7.751%. However, Lubis et al (2014) found the opposite the genetic diversity of cob dry weight was high in acid soil.…”

“…The breadth or narrowness of the genetic diversity of a trait was obtained from the Coefficient of Genetic Diversity (CGD) value category, using the formula developed by Azrai et al (2016) as follows:…”

“…G/ σ 2 P) x 100 % Where: H 2 is a broad heritability, σ 2 G is genetic diversity, and σ 2 P is phenotypic diversity. Low heritability if H 2 <20%, moderate is 20-50%, and high if H 2 >50% (Lubis et al 2014;Azrai et al 2016).…”

“…The success of the selection is highly dependent on genetic diversity, heritability (Dar et al 2015;Admire et al 2018;Sadimantara et al 2021;Rachman et al 2022;Yali 2022), effectiveness of selection procedures and the environment (Azrai et al 2016;Aci et al 2018). The category of genetic diversity can be seen from the value of the coefficient of genetic diversity since this value measures the magnitude of the genetic variation of a trait (Lubis et al 2014;Dar et al 2015).…”