| Drought is one of the important factors affecting the yield stability of maize (Zea mays L.) in China and some other areas in the world. In order to solve drought and water shortage problem, breeding hybrids with drought resistance is an important method besides water saving engineering. Biologic theory of breeding hybrids with drought resistance is that there exist differences among different genotypes and different development stages for the same genotype. Evaluating on drought resistance of maize germplasm in China, genetic analysising of drought resistance and establishing of the molecular marker-assisted selection (MAS) are important and essential for breeding hybrids with drought resistance.I The drought resistance of the elite inbred lines applied in breeding and production in China was evaluated in different drought conditions according to drought coefficient and drought index. The results showed that there existed inbred lines with different types of drought resistance and of high yield and drought resistance. The analysis revealed that some inbred lines showed drought resistance in both middle and later period of growth, some only in one period. The high yield with high drought resistance was realized by different methods, some through higher index of kernel number and 100-kernel weight, other through higher index of kernel number and other through higher index of 100-kernel weight. It is possible to breeding lines with bo.th high yield and high drought resistance by a certain breeding methods.II The drought resistance of the elite inbred lines applied in breeding and production in China was evaluated in drought conditions.The results also showed that there existed inbred lines with different types of drought resistance and of both high yield and high drought resistance. Taking the average drought resistance coefficient of the materials as standard, the coefficient of 39 inbred lines was larger than the average in two years. They were 4F1, D857, D888, D978, H21, Mo113, Mol7, P138, Ben 7884, Chang 3, Chang 72, Danhuang 02, Dong 237, Hai 014, Hai 1134, Hu 803, Huang C, Huotanghuang 17, Ji 4112, Ji 853, Longkang 11, Luyuan 92, Qi 205, Shen 5003, Shuang 741, Tian 77, Tianyasi, Tie 7922, Wenhuang 413, Xi 502, Yan 414, Ye 515, Ye 8112, Yu 374, Yu 87-1, ZaC546, Zheng 22 and Zheng 653. Taking the average drought resistance index of the materials as standard, the index of 32 inbred lines was larger than the average in two years. They were 4F1, D854, D857, D863, H21, Mo17, P138, S22, Ben 7884, Chang 3, Danhuang 02, Hai 014, Huotanghuang 17, Ji 4112, Longkang 11, Qi 205, Shen 5003, Shuang 741, Tie 7922, Xi 502, Yan 414, Yan 812, Ye 488, Ye 515, Ye 8001, Ye 8112, Ye 832, Yu 87-1, Za C546, Zheng 22, Zheng 32 and Zheng 653.III The drought resistance of 99 maize hybrids applied in production in China was evaluated indrought conditions. The results showed that drought restricted the development of hybrids compared with the normal condition. There existed significant variation among different genotypes. The drought resistance of 28 hybrids was outstanding according to drought resistance coefficient and index and cluster. They were Dan 638, Jingke 238, Nongda 108, Nongda 3138, Ludan 50, Sidan 136, Gaonongl, Denghai 1, Linao 1, Jidan 255, Nongda 4967, Danyul3, Zhengdan 958, Jinzao 13, Simi 21, Hudan 4, Jidan 257, Tiedan 10-2, Zhongdanl20, Dongdan 52, Jindan 35, Quanxingyu 8, Shen 9729, Zhongdan321, Shendan 12, Shendan 13, Fuyou 1 and Tiedan 17. These hybrids were the achievement of Chinese maize breeders and important germplasms for drought resistance breeding.IV The root development characteristics and its relation to the canopy growth of maize hybrid with different drought resistance were compared by the soil column culture in two conditions: irrigated and water stress. The results showed that root development characteristics and its relation with canopy growth of maize hybrid with different drought resistance in water stress were similar to that in irrigated condition. The root development characteristics among differ...
|
PDF Full Text Request