GENETIC VARIABILITY AND DIVERSITY FOR SHOOT/ROOT PARAMETERS UNDER EARLY DROUGHT STRESS CONDITION IN SORGHUM (SORGHUM BICOLOR (L.) MOENCH) GENOTYPES
K. RAJARAJAN*, K. GANESAMURTHY AND A. YUVARAJA
Centre for Plant Breeding and Genetics,
Tamil Nadu Agricultural University Coimbatore-641 003
*(e-mail : rajesh.tinu@gmail.com)
(Received : 10 January 2018; Accepted : 6 February 2018)

SUMMARY

Thirty sorghum genotypes were evaluated for their genetic potential to drought tolerance based on shoot/root parameters. The seedling traits as shoot length, root length, fresh root weight and dry root weight were studied under control as well as water stress condition. The traits dry root weight, fresh root weight, shoot length and root length were found most affected due to water stress. Further, the coefficient of variation, heritability, genetic advance and diversity for shoot/root parameters of sorghum genotypes under moisture stress condition was studied. High estimates of heritability were observed for dry root weight (92.05%), fresh root weight (90.40%), shoot length (83.84%) and root length (61.40%). Genetic advance as per cent of mean were observed for dry root weight (69.89), fresh root weight (64.87), shoot length (43.31) and root length (20.17). The diversity of genotypes was studied based on D2 statistics and grouped into 11 clusters and each cluster revealing considerable amount of genetic diversity. The genotypes in the cluster I (ICSR93001, ICSV95022, AS160, MS8444) and II (DRT1030, B35, CO26) are identified as superior genotypes for early drought tolerance and suggests the possibilities of improvement of these characters through selection for drought tolerance breeding programme.

Key words: Sorghum, drought, shoot/root, genetic variability, diversity

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