Linkage Groups in Sorghum

Four crosses involving five varieties of Sorghum vulgare, Dodaniya, Redar, M. 35-1, Vidul and Male Sterile CK-60 were studied. Twenty-two different characters were studied and all of them exhibited typical monohybrid ratios in F₂. Joint segregation study revealed presence of linkage in 33 combinations. It was possible to separate these 33 combinations in four different linkage groups; three of them were identified with 3rd, 4th and 5th of the previously reported seven linkage groups. The fourth being entirely new, was designated as the eighth linkage group.

Two loci, Gep and Mu controlling panicle colour at emergence and leaf blade disposition respectively were added to the 3rd linkage group reported earlier. Similarly, Bs, Stp, Oy and Gh controlling basal sterility, conical stigma, ovary colour and glume hairiness respectively were added to the 4th linkage group and the gene A controlling presence of awns to the 5th group reported earlier.

The newly identified eighth linkage group consists of five gene loci, viz. Ra (Dry anther colour) Rsg (Dry stigma colour) Ysg (Fresh stigma colour), Lr (Dry leaf colour) and Rr (Pericarp colour).