Refering to corn breeding literature at home and abroad,the possible ways to improve the efficiency of maize breeding were discussed. The results showed that through the summary and reflection on breeding objectives and strategies,and improvement and optimization of breeding techniques and methods,as well as adjustment and simplification of experimental design and implementation,the breeding cost would be greatly reduced,and the breeding efficiency would be improved.

We studied the effects of Cistanche deserticola on biomass and contents of carbohydrates in the host plant,Haloxylon ammodendron.The total biomass of H.ammodendron was reduced by 23.30 g,but the biomass of C.deserticola was 8.31 g,the photosynthetic shoot biomass decreased by 30.0%,the trunk and two-year branche biomass decreased by 3.0%,and the root biomass decreased by 18.7%.The soluble sugar content in shoots of H.ammodendron parasitized by C.deserticola increased,but the soluble sugar stored in photosynthetic shoots and root decreased to different levels.Most starch and total non-structural carbohydrate(TNC) was stored in roots and the trunk,but starch was the major component.The concentrations of starch and TNC in photosynthetic shoots and root of H.ammodendron were higher than in those in artificially planted C.deserticola.

In order to resolve the problems of low accuracy and efficiency in the yield trials for maize breeding,and find a good method for maize hybrid identification,the appearance of maize yield in different growth environments in this article.The productivity,competitive ability and compensative ability were estimated,and the relationship between them and other traits were analyzed.It is showed that the competitive ability negatively related to productivity,and it positively related to some plant-type traits,such as plant height,tassel branch number and leaf area.These results will supply a new way for maize breeding.

The plant-type traits of 56 maize hybrids and 35 inbreds of their parents were analyzed in this article.The results showed that the correlation between plant-type and yield traits of maize hybrids is rarely significant,while that between different plant-type traits of maize inbreds is commonly significant.The cluster analysis of maize inbred plant-type traits could help finding the similarity of their morphological characters,so as to reflect their genetic variations.These results have somewhat directions for maize breeding.