The Effect of Wheat Mixtures on the Powdery Mildew Disease and Some Yield Components

Mixtures composed of five wheat cultivars,Jingshuang 16,Jing 411,Jingdong 8,Lunxuan 987,and Baofeng 104,with different levels of resistance against powdery mildew were tested for their potential containment of the disease development in the field and for the influence on grain yield and the content of crude protein in the years 2007 and 2010.The plots were inoculated artificially with mixed isolates collected in the fields and propagated in the greenhouse and the disease was scored in 7 d interval during the two growing seasons.It was indicated that certain combinations,e.g.,Jingdong 8：Lunxuan 987,Jingdong 8：Baofeng 104,and Jing 411：Jingdong 8：Baofeng 104,showed positive efficacy on the mildew.The cultivar combinations tested in 2007 showed increase of grain yield,while most of the combinations tested in 2010 did not show the increase.The differences of the increases or decreases were not statistically significant except combinations Jing 411：Jingdong 8：Baofeng104,Jingshuang16：Jingdong8：Lunxuang 987 and Jingshuang 16：Jingdong 8：Lunxuan 987：Baofeng 104,which showed the decrease of the grain yield.The mixtures did not show influence on the content of crude protein in grain.More cultivar combinations need to be tested.

Mixing trait-based corn(Zea mays L.)cultivars increases yield through pollination synchronization and increased cross-fertilization

Abiotic stress such as high temperature at flowering is one of many conditions reducing yield of corn(Zea mays L.).Mixing corn cultivars with diverse functional traits increases within-crop diversity and provides a potential means of mitigating yield losses under stress conditions.We conducted a three-year field study to investigate the effects of cultivar mixtures on kernel setting rate,pollen sources,and yield.This study consisted of six treatments,including two high temperature-tolerant(HTT)monocrops of WK702 and DH701,two high temperature-sensitive(HTS)monocrops of DH605 and DH662,and two HTT–HTS mixtures of WK702-DH605 and DH701-DH662.The anthesis–silking interval(ASI)was 0.9–1.6 days shorter in mixtures than in monocrops.Kernel setting rate was increased in mixtures(86.4%–88.7%)compared with those in monocrops(74.7%–84.1%)as a result of synchrony and complementarity of pollination.Grain yields of the HTT–HTS mixtures increased by 13.3%–18.7%,equivalent to 1169 to1605 kg ha^(-1),in comparison with HTS corn monocrops.The results of SSR markers showed that crossfertilization percentage in corn cultivar mixtures ranged from 29.3%to 47.8%,partially explaining yield improvement.Land equivalent ratio(LER)was 1.12 for corn mixtures and the partial land equivalent ratio(e.g.,>0.5)showed the complementary benefits in corn mixtures.The results indicated that mixing corn cultivars with diverse flowering and drought-tolerance traits increased yields via pollination synchrony.

Cultivar Mixture Cooperation(CMC)of rice varieties(lines) with different blast resistant gene

We studied Cultivar Mixture Cooperation(CMC)of rice varieties(lines)by screening mixture ofrice varieties which possess different genes,1983-1996.