Genetic diversity in tropical maize inbreds under well watered and water stress condition

Abstract

Maize being a widely grown crop succumbs to changed climatic conditions especially drought. Breeding for drought tolerant maize hybrids necessitates selection of diverse drought tolerant inbreds which can help in development of heterotic hybrids suitable for both normal and moisture stress situations. Hence, the present study has been conducted to assess genetic diversity among 28 tropical maize inbreds based on physiological, phonological, yield and yield components under well watered and water stressed condition. Seven clusters were formed under water stress and 14 clusters under well watered condition. Cluster I was largest with 15 inbreds in water stressed and nine under well watered condition. There were many mono-genotypic clusters under water stressed condition (5) and under well watered condition (13). Based on inter-cluster distance , the maize inbred PDM 77-4 and  PDM 4641 belonging to mono-genoypic clusters were diverse both under well watered and water stress condition Shelling percentage (41.2 %, 33.1 %), grain yield (20.5 %. 25.9 %), cobs per plant (17.8 %. 19.1 %), contributed maximum towards genetic divergence both under well watered and water stress condition and hence these characters may be given weightage while selecting diverse inbreds to develop superior hybrids suitable for both well watered and water stressed condition. The genotype PDM 4541 exhibited higher relative water content, lower days to 50 % tasseling, 50 % silking with reduced anthesis silking interval under water stressed condition and hence can be a potential genotype in developing hybrids suitable specifically for water stressed condition.   Maximum cob length, cob girth, kernel row number, number of kernels per row, 100 grain weight and grain yield was distributed in different mono-genotypic clusters having maize inbreds CML 451, CAL 1426-2, CML 563 and PML 54 and hence these inbreds can be used in population improvement programme to derive inbred lines combining many productive traits.