Pengembangan Metode Seleksi Galur Murni Jagung Pulut (waxy corn) Toleran Kekeringan dan Introgresi Gen opaque-2 (oo) dengan Marka SSRs (Simple Sequence Repeats)

Abstract

The Dissertation study the development of selection method corn parent inbred lines for parents at hybrid waxy corn tolerant to drought and introgression of opaque- 2 (oo) gene by using SSRs (Simple Sequence Repeats). The first experiment was to determine relation of waxy corn genotype kinship based on DNA band pattern by using SSRs marker and correlation among taxonomic distance matrix averages based on morphological performance, and similarity coefficient based on DNA band pattern getting from SSRs marker. The result showed that genetic variance of the tested material was high enough. It was indicated by polymorphism value of 0.62. Dendogram construction based on UPGMA was able to distinguish one genotype to the others. According to genetic similarity, the genotypes could be grouped into three clusters characterized by the genotypes with similar pedigree code with cofenetic correlation coefficient (r) 0.88 categorized good fit for handled waxy corn genotype groups. However, Correlation value between taxonomic distance matrix based on morphological performance and similarity coefficient based on DNA band pattern according to goodness of fit criteria was categorized as very weak. The information could used in selecting the parent and become as one of strategies in hybrid maize breeding program. The second experiment was conducted to estimate combining ability and heterosis value of ten waxy corn genotypes having high amelopectin, tolerance to drought stress environment as parent candidate of hybrid formation. The result indicated that several genotypes having good combining ability value for grain weight character per plant and interval silking anthesis under stress and drought stress environment. Grain weight character per plant on without stress and drought stress environment showed the same combining ability value, while interval silking anthesis on without stress and drought stress environment revealed different combining ability value. This information is important to determine direct or indirect selection method in selecting maize genotypes which tolerant to drought stress environment. The third experiment was conducted to introgress recessive gene opaque-2 mutant from QPM genotypes to waxy corn genotypes by using MAS (Marker Assisted Selection). The result showed that specific SSRs marker phi057 was proved effective and efficient to be used in selecting genotypes of CML141 x PTBC4-7-1- BB and CML142 x PTBC4-10-1-BB progenies that were introgressed with homozygote recessive opaque-2 (oo) gene. Selection result utilizing MAS had a tendency to follow relative segregation on every selfing generation and the number of CML141 x PTBC4-7-1-BB and CML142 x PTBC4-10-1-BB progenies were screen with phi057 specific marker. Was identified 57 genotypes of PTBC4-7-1- BBo2 and PTBC4-10-1-BBo2 as genetic materials in development of hybrid maize variety having high amilopectin and protein content. The fourth experiment was carried out to obtain information on yield potency and waxy corn genotypes having opaque-2 gene as parent candidate of hybrid variety development. The result showed that the tested genotypes had good specific combining ability value good enough to one of the good testers either with CML144 or CML156 for grain weight character per plant, and grain weight character performance of top crossing 57 genotypes with the two very varied testers. The effect of environment factor was more dominant than genetic factor on crossing with CML154 and the effect of genetic factor was more dominant than environment factor on crossing with CML156. Inbred genotype of MrP-7-1-20BBo2 had specific combining ability with CML154 and potential parent candidate in the program aimed at obtaining high yielding hybrid. Inbred genotype of MrP-10-1-13BBo2 had good specific combining ability with CML154 and CML156 as well as potential as parent candidate in the program aimed at obtaining high yielding hybrid.