Diversification of QPM germplasm through magic Approach

Abstract

Maize is considered as ‘Queen’ of cereals, however it is deficient in two essential amino acids i.e. lysine and tryptophan. Quality Protein Maize (QPM) has double the amount of tryptophan and lysine content as compared to normal maize. The QPM germplasm has narrow genetic base thereby difficult to improve for high grain yield. The QPM germplasm needs to be diversified through different means like Mass Assisted Selection (MAS) and Multi parent Advanced Generation Inter cross (MAGIC) approach. The present study was conducted keeping in mind the diversification of QPM germplasm using MAGIC approach. A set of 48 inbred lines (24 QPM and 24 normal lines) were selected on the basis of perse performance and these lines were crossed with two diverse testers i.e. LM 13 & LM 14 to generate the information on heterotic grouping and simultaneously diversity studies were also carried out using SSR markers. The dendogram clearly showed that the QPM and normal germplasm is falling in different clusters. Based on heterotic grouping data and diversity analysis the lines were selected for making cross combinations within heterotic groups. The normal lines of one group were crossed with QPM lines of the same group and vice versa. Four crosses were made in similar fashion viz., for heterotic group A, DML 2052  DQL 2111 and DML 1837  DQL 2303and for heterotic group B, DML 1596  DQL 2180 and DML 1812  DQL 2290. The two crosses made for group A will again be crossed among themselves similarly in case of group A and then new lines will be synthesize. Desirable QPM lines will be advanced to next generation based on the biochemical data and these lines after reaching S6 S7 stage, will be tested for per se performance and then best lines will be used for crossing programme for development of new hybrids