Use of gametocide for emasculation in Soybean (Glycine max (L) Merr.)
Authors:
S K Lal*, C Devkumar (1), R L Sapra and K P Singh, Division of Genetics, Indian Agricultural Research Institute, New Delhi, 1-Division of Agriculture Chemicals, IARI, New Delhi
Abstract:
Hybridization is a tedious operation in soybean. Gametocides have been used in a number of crops to induce male-sterility either for hybrid seed production or as a substitute for hand emasculation. However, there is no report of use of gametocide on Soybean. Ethyl 4'fluorooxanilate at the rate of 1000 ppm was used for inducing male -sterility. Preliminary study shows that the pollen sterility varied from 20.03% to 55.55% in the treated samples as compared to 1.37% to 2.63% in the control. The effectiveness of the gametocide can be improved by increasing the quantity of the gametocide used or by spraying at an appropriate stage. Even with 50% sterility it can be successfully used in combination with a dominant morphological marker for emasculation.
Induced Variation in Quantitative Traits due to Physical (gamma rays), Chemical (EMS) and combined Mutagen Treatments in Soybean [Glycine max (L.)Merrill]
Authors:
Archana Patil, Taware S. P. and Raut V. M.
Abstract:
Indian Soybean variety, MACS-450 has semi determinate growth habit, medium maturity and high yield potential which is very well adapted to agro-climatic conditions of Southern India. Seeds of this variety were exposed to various doses of Y rays, ethyl methane sulphonate and combination of both. Observations on percentage germination, percentage leaf abnormalities, percentage survival, days to maturity, plant height, pods per plant, seed weight per plant and yield kg/ha were recorded on M1 generation. Likewise percentage reduction in various quantitative characters through various treatments was also recorded. The results indicate dose related effect of mutagenic treatments on quantitative traits. 20 to 25 Kr Y rays dose and 0.10 to 0.20% EMS dose may be optimum to obtain maximum variations in qualitative as well as quantitative traits in M2 population.
Identification and sequence analysis of a RAPD marker tightly linked to the Rsv1 locus in soybean
Authors:
Z. Li , R. L. Nelson, R. L. Bernard, and Y. Peng
Abstract:
'Williams' and three near-isogenic lines (isolines) with soybean mosaic virus (SMV) resistance were used to identify a random amplified polymorphic DNA (RAPD) marker linked to the locus conferring resistance to SMV. A RAPD marker was found to be present in Williams and absent in three isolines of Williams with SMV resistance. Three F2 populations developed from the crosses of Williams x L81-4420, Williams x L92-8151, and Marshall x Kanro were produced to verify the linkage between the fragment and SMV resistance gene. A 1,000 base pair fragment, designated OPN-111000, generated by the primer OPN-11 was located approximately 1.2±1.2 cM in repulsion phase and 1.8±1.3 cM in coupling phase from Rsv1, a gene for resistance to SMV. In a survey of other germplasm, OPN-111000 was found linked with either Rsv1 or rsv1. F3 families derived from F2 resistant plants were used to confirm the F2 genotypes. Using this marker, homozygous and heterozygous SMV resistant plants could be easily distinguished based on the fragment intensity. By cloning and sequencing the fragment, the RAPD marker was converted to a SCAR marker. This SCAR marker can be used reliably for marker-assisted selection of Rsv1 locus, map-based cloning or further SNP marker development.