Study On The Utilization Of Derived Lines From Popcorn×Normal Corn Crosses

Using normal com germplasm is a main way to improve grain yield and agronomic straits of popcorn inbreds, and to broaden the germplasm basis of popcorn while maintain its excellent popping characters. But little research was done on the character performance and utilization of advanced pedigree selected stable lines from popcorn x normal corn crosses.This research systematically analyzed the popping characteristics, ear-kernel and plant characteristics of advanced pedigree selected stable lines developed from two popcorn x normal corn crosses, Dan 232×N04 and BJian8×N05, through 6 successive generations of selection. 324 testcrosses were made between 53 selected stable lines developed from Dan232×N04 and the popcorn parent N04, and 6 elite popcorn inbreds, showing heterosis with N04, using NCII genetic design. The performance of all testcrosses and the GCAs of all inbred parents, and their SCAs were all analyzed for each character. And 301 testcrosses were made between 57 selected stable lines developed from Dan232×N04 and the same 6 elite popcorn inbreds, and their performance were analyzed for all characters. The results were as follows:(1) There were differences among selected lines in each generation in average value, range of variation, coefficient of variability and the number of plants with better performance than the popcorn parent. But the difference was smaller for popping rate. The ear-kernel weight and 100- kernel weight of selected lines from successive self after 1～2 backcrossing with the popcorn parent were smaller than that of the selected lines from continuous self, but it was opposite for popping rate and popping fold. The selected lines were all few through continuous self for the two popcorn × normal corn crosses, Dan232×N04 and BJian8×N05. So, the probability was low to develop elite popcorn inbreds using normal pedigree selection method for the popcorn × normal corn crosses. Significant improvement could be obtained through 1-2 backcross with the popcorn inbred, and following with normal pedigree selection. In this way, ear-kernel and plant characteristics were also improved at the same time. For Dan232×N04, just one generation of backcross could bring significant improvement.(2) The GCAs and SCAs of 53 selected lines from Dan232×N04 were significantly different for all characters. Comparing with the popcorn parent N04, the...