Genetic architecture of grain quality characters in rice (Oryza sativa L.)

Analysis of generation mean was carried out in six crosses of rice viz., ADT 41 / ADT 46, ADT 41 / CO 47, ADT 41 /TKM 9, ADT 41/ Jeeragasamba, ADT 41/ACM 98003 and ADT 41/AS 90033 for hulling percentage, milling percentage, head rice recovery, kernel length, kernel breadth, kernel L/B ratio, kernel length after cooking, linear elongation ratio and alkali spreading value. The scaling test showed the presence of epistatic interactions for all the nine grain quality traits studied. Milling percentage and linear elongation ratio were governed by additive, dominance and epistatic interactions of additive x additive, dominance x dominance and duplicate epistasis. Hulling percentage was governed by additive, dominance and duplicate type. Head rice recovery was under the control of additive, dominance, dominance x dominance and duplicate epistasis. Kernel length and kernel breadth were predominantly under the control of additive, dominance, additive x dominance and duplicate gene interactions. Kernel L/B ratio and kernel length after cooking were influenced by additive, additive x dominance and duplicate type. Dominance, additive x additive and duplicate type of gene actions influenced alkali spreading value. The other four grain quality traits viz., water uptake, volume expansion ratio, amylose content and gel consistency were under the control of non-additive gene action. To explore both additive and non-additive type of gene action it was suggested to postpone the selection to later generation in pedigree breeding programme.