The New Varieties Breeding Of Early Autumn And Heat Resistant Cabbage

Cabbage is one of the important vegetable crops in spring and autumn in China. Early autumn cabbage is encountering on high temperature and serious pest during growing period. Currently on the market, the outer leaves of strong heat-resistant cabbage cover more waxy, but the heat resistance of green cabbages are relatively poor, Therefore our aim of study is to select the elite inbred lines by agronomic and quality traits, then make F1hybrids using Griffing diallel crosses method and investigate their heat resistance, agronomic traits, quality traits and disease resistance by molecular markers, further analyze the combining ability of hybrid. Meanwhile, we also measured the phenotypes of some potential hybrids by agronomic and quality traits, and ranked them based on the comprehensive characters using principal components analysis in2012and2013years respectively. The main results are as follows:1. Heat-resistance, agronomic traits and quality traits were identified in34cabbage inbred lines and self-incompatible lines.5good heat-resistant green inbred lines are selected as parent to make hybrid combinations. The selected inbred lines are as follows:WG-11F-2-1-2-4, N9-2-1-2, N7-5-3-1,21-3-1-6and66-2-1-1-3.2.10cross combinations were performed from selected5elite parents using Griffing diallel model. We identified their heat resistance by simulation experiment in controlled incubator and then measured their physiological and biochemical index, The results indicated that the strongest heat resistance is Rh4, followed by Rh3, Rh2and Rh1; and the best one also is Rh4based on agronomic and quality traits, followed by Rhl and Rh3; The results of disease measure by molecular marker indicated that the combination Rh6, Rh8and Rh10are resistant to black rot, blight, downy mildew and TuMV together.3. The combining ability of10hybrid combinations was analyzed, the results showed that the parent P2and P5have significantly positive effect on chlorophyll content and heat resistance, which are suitable to make heat-resistant green cabbage combination; Rh4is the best combination based on the SCA values of yield, heat resistance, sugar and Vc content.4.163hybrids were obtained in2012and2013, based on the results of phenotype, agronomic and quality traits of good hybrids were further investigated. The results demonstrated that the best early maturing cross is12G115; the best middle maturing cross is12G155; the best late maturing cross is12G197for the hybrids in2012. The best cross is13G220for the results in2013.