DNA Aided Introgression of Opaque-2 Allele for Development of Quality Protein Maize

To improve the nutritional quality of maize, introgression of the opaque-2 (o2) trait to normal maize lines is essential. The QPM donors used in present study were; CML 161, DMR QPM 58, CML 176 and CML 141 whereas, normal maize inbreds were CM 212, V338, V361, V336, V341, V351, CM141 and V335. All the selected lines were subjected to parental polymorphism survey between non QPM and QPM lines using CIMMYT based three SSR primers viz. , phi057, umc1066 and phi112. Two markers viz. , phi 057 and umc1066 exhibited co-dominant reaction while phi 112 was dominant in nature. Finally two combinations CM141 CML 176 and V335 CML 161 were considered for conversion programme. Foreground selection was exercised using opaque-2 specific marker umc1066 in BC1 and BC2 generations while background as well as foreground selection was exercised in BC2F1 generation to recover the genome of recurrent parent up to extent of 82.5 to 98.5 percent with the help of 98 SSR markers distributed across the genome. The tryptophan concentration in endosperm protein was significantly enhanced in all the three classes of kernel modification viz. , less than 25 %, 25-50 % and more than 50 % opaqueness. So, the converted maize lines had almost twice the amount of Lysine and Tryptophan than normal maize inbreds.