Central Rice Research Institute, Cuttack
Online published on 25 January, 2012.
Six crosses involving five japonica parents, and one indica extract of cross (A 26 × N 22) were studied for the inheritance of genes governing dwarf habit, liguleless condition, anthocyanin pigmentation in leaf blade and linkage relationship of genes governing these characters. In this attempt, a specific marker gene (d2) from japonica was transferred to indica backgrond. The true breeding dwarf indica extract was isolated and crossed to Marker 18 for linkage study.
Dwarf habit was governed by a single recessive gene. Two recessive genes were responsible for the liguleless condition. One to two genes for purple colour including an inhibitory gene were involved in the expression of purple leaf blade colour. Cross over values of 32% between d2 and p1 and 21.1% between the genes p1 and lg obtained in the cross (A26 × N22) extract × Marker 18 confirm their position in group II of Nagao and Takahashi. Nejireba 803 and Shima-waigate 813 were inferred to possess the genes d2 and d3 respectively.
The study showed that the linkage relationship of genes in indica and japonica sub-species was more or less same except for some minor differences in the intensity of linkage.
