ASSESMENT OF SOME GENETIC DIVERSITY OF SOME COTTON CULTIVARS IN MINNA NIGER STATE, NIGERIA.

Abstract

Cotton (Gossypium sp.) is an important cash crop of the family Malvaceae which produces lint and seed that serve as food and raw materials for textile and seed crushing industries. Despite, the economic importance of this crop to human livelihood, it total production remains far below the national requirements for textile and oil mills due to obstacle posed by poor seed quality and germination.Pollen quality and pollination play a fundamental role in fertilization and seed sets. Therefore, study on pollen parameter are essential for understanding fertility of this crop and its improvement. A total of six accession of cotton (SAMCOT 8, 9, 10, 11, 12, and 13 were evaluated for morphological parameters on the field and their pollen studies was carried out in the laboratory at maturity. The accessions were evaluated for plant height, number of branches, days to bract square and boll formations, pollen viability and size (both intine and exine). The results of the morphological parameters showed a significant variations in plant height with SAMCOT 008 having the highest plant (49.75cm) and SAMCOT 010 had the least (26.75cm) at the end of the studied period. In terms of earliness to maturity SAMCOT 008 mature earliest, with 37 days and 55 days for bract square and boll formation while SAMCOT 013 had the least maturity status of 56 days and 77 days for both bract square and Boll formation. Significant variations were recorded in the pollen parameters with highest percentage viability recorded in SAMCOT 09 (94.25%) and the lowest in SAMCOT 08 with value of 77.78%. Variation in the pollen size (both intine and exine) among the accession recorded, with the lowest intine (20.50µm) and exine (27.00µm) in SAMCOT 011. The highest pollen intine was recorded in both SAMCOT 010 & SAMCOT 012 (25.50µm) and exine (33.00) in SAMCOT 008. The highest pollen size, plant height couple with least days for bract square and boll formation might indicate the presence of genes for earliness in the accessions which is a good trait for selection and improvement in breeding programs.