Analysis Of Combining Ability And Heterotic Groups Of 14 Inbred Lines In Maize(Zea Mays L.)

In the study, 14 inbred lines breeded by Pingliang Maize Breeding station were used to make a total of 49 testcrosses with NCII. The combing ability, heterosis and genetic indexes of main traits of 14 inbred lines were estimated, and the heterosis groups and heterosis patterns of these inbred lines were studied with SSR markers. The main results were summarized as follows:1. The analysis of the main agronomic traits GCA effect showed that integrated characters of FN283-5, FN290-4, FN186-2, FN244-1, Q897-2 and Q898 performed better, Q897-2 was the best of all. The hybrid with this inbred as parent performed lower ear height, less total leaf number and spike leaf, longer ear length and diameter, little bald or no bald, more ear row number, moderate grain number, higher 100 seed weight and yield. In the breeding work which should be focused on using.2. Heritability analysis results showed that the narrow sense heritability of plant height, ear position high, spike leaf, total leaf number, ear diameter and ear row number was higher, driven by gene additive effect was larger, less affected by environmental variation and suitable for early generation selection. Kernels per row, kernel weight and seed rate of narrow sense heritability was lower and more affected by environment. Which should be suitable of late generation selection.3. The yield heterosis analysis of each hybrid combinations showed there were 10 hybrid combinations which yield higher than the control. The frequency of Q897-2, Q844-1, Q898,10ZX1332-1 and Q756-2 in P1 group were counted as follows: 30%, 20%, 20%, 20% and 10 %; FN283-5, The frequency of FN290-4, FN186-2, FN420-1 and FN244-1 were counted as follows: 30%, 20%, 20%, 20% and 10%. FN186-2 / Q897-2 had highest yield, FN283-5 / Q898 yield followed, FN244-1 / Q897-2 output ranked third.4. The results of SSR analysis showed that the 14 inbred lines were divided into four subsets where PA subsets(42.86%), Lvdahonggu subsets(28.57%) Lancaster and Sipingtou each accounted for 14.29% which were not distributed in Reid and PB subpopulation.5. Model of heterosis analysis indicated that PA×Sipingtou(SS/NSS) could generate strong heterosis. This conclusion is in accordance with commonly used heterotic patterns in our country. The combination modes of PA×Lancaster(SS/NSS) and Lucia Red Cob× Sipingtou(SS/NSS) in varying degrees have heterosis. These two heterotic patterns also should be used in the breeding work.