Genetic Studies of Elite Landraces of Maize for Yield and Its Components
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Date
2013
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JNKVV
Abstract
ABSTRACT
The present investigation entitled “Genetic studies of elite landraces of maize for yield and its components” was carried out at Seed Breeding Farm in Department of Plant Breeding & Genetics, J.N.K.V.V. Jabalpur during Rabi season 2012-13. The experimental material for the present investigation was comprised of a collection of 62 desi maize lines collected from different parts of M.P. with 2 checks. These genotypes were planted in randomized completely block design with three replications. This investigation was carried out to estimate the genetic variability, heritability, genetic advance correlation coefficient, path coefficient analysis, divergence analysis and principal component analysis between yield and its component characters, to identify the importance of individual character and formulating selection criteria for improvement in yield. Observations were recorded for 18 quantitative and 2 qualitative characters
In the present investigation, the analysis of variance revealed that the mean sum of square due to genotypes were highly significant for all the traits.
Out of 18 traits studied eight traits viz., ear height from ground, 100-grain weight, ear weight, grain yield per plant, biological yield per plant, harvest index (%), number of prop roots, and lodging (%) showed high magnitude of variability in terms of PCV and GCV estimates, while moderate amount of genetic variability was observed for four traits viz., plant height, ear length, number of row per ear and stem girth. On the other hand Five characters viz., days to male flower initiation, days to female flower initiation, days to 50 per cent tasseling, days to 50 per cent silking, days to maturity recorded low PCV and GCV estimates.
High heritability coupled with high genetic advance as percentage of mean was recorded for plant height, ear height from ground, ear length, number of rows/ear, 100-grain weight, ear weight, stem girth, ear girth, grain yield per plant, biological yield per plant, harvest index (%), number of prop roots and lodging (%).
Grain yield per plant was observed to be positively associated with ear weight, biological yield per plant, cob diameter, 100 grain weight, ear length, ear height from ground, stem girth, harvest index, plant height, number of rows per ear and number of prop roots. While Path coefficient analysis has revealed that biological yield per plant, harvest index (%), days to 50% male flowering and ear weight were the main yield contributing characters and should be given more emphasis
The percentage contribution towards genetic divergence by all the characters revealed that, biological yield per plant contributed most towards genetic divergence followed by remaining characters in descending order viz. grain yield per plant, ear weight and plant height these four traits accounted for 93.06 per cent of total variability. On the basis of D2, 64 genotypes were grouped into 5 clusters. Maximum numbers of genotypes were recorded in cluster I having 60 genotypes followed by cluster II, cluster III, cluster IV and cluster V which had only one genotype in each.
Cluster I showed maximum intra cluster D2 value while Cluster II, III, IV and V were mono-genotypic hence, showed no intra cluster divergence. On the basis of inter-cluster distances, high inter cluster divergence was observed between cluster I and cluster V, followed by cluster I and IV, and cluster III and V, while it was lowest between clusters II & III. By selecting diverse parents from these clusters crop improvement work in maize can be strengthened.
In principal component analysis characters contributed for Yield can be highlighted by PC1, PC2, PC4, whereas characters for plant height and ear height from ground can be expressed by PC3 and stem girth can be included in PC5. On the basis of principal component analysis, correlation and path analysis genotype JLM 22 was found best for yield and its components followed by JLM 51, HKI 13441, JLM 30, JLM 2, JLM 33, JLM 23, and JM 216. These genotypes must be utilized for further breeding programme.