Punjab Agricultural University
†Present address: The International Rice Research Institute, Los Baños, Laguna, Philippines.
*Part of the thesis submitted by H. S. Brar in partial fulfilment of the requirements for the Master of Science degree.
Studies involving 28 cross combinations between parents representing major seed colours in chick pea showed that five independent loci were involved in the production of seed colour. One of the five pairs of genetic factors Pp which had been previously found to differentiate pink and white flowers was also responsible for differentiating buff and related seed colours from dark seed colours like fawn, brown, green, and grey or black. The recessive allele (p) was epistatic over other loci influencing seed colours and its dominant condition (P) was essential for the production of fawn and darker seed colours.
The other four genetic factors were designated as S1s1, S2s2, S3s3 and S4s4; s1 produced fawn colour and S1 reddish brown; S2 had no effect but s2 produced seal brown colour and was epistatic over the S1 locus; S3 was ineffective and s3 produced green seed colour and was epistatic over the other two loci; S4 was epistatic over all the three loci and produced dark grey seeds in the presence of S2 and black seeds in the presence of s2.
Additional studies were carried out to determine the relationship between four pairs of genetic factors for seed colour and eight mutant loci. All seed colour genes were inherited independently of the loci for Simple Leaf (Slsl), Giant (Gtgt), and Flat Stem (Fsfs) mutants. Also, S2s2 and S3s3 assorted independently of Tltl (Tiny Leaf), Stst (Stalked Leaflet), and Dfdf (Double Flower) and S4s4 independently of Rprp (Round Pod) and Dfdf (Double Flower). The locus Bubu did not show any linkage with S1S1, S3s3, and S4s4 but was linked with S2s2 with a cross-over value of 27.30 per cent.
