大白菜单体的鉴定及其染色体行为研究

Identification of Several Monosomics in Chinese Cabbage and Observation of Their Chromosome Behaviors

以同源四倍体大白菜小孢子植株为材料,采用根尖染色体数鉴定的方法,从534个小孢子植株中筛选出9株2n–1=19的植株,经核型分析和离体繁殖初步获得了3号、5号和6号3个单体。3个单体生殖生长期植株和花蕾形态及花粉特征与二倍体差别明显,各单体间花蕾形态差异明显。在减数分裂终变期或中期Ⅰ,单体染色体主要以单价体的形式存在,后期Ⅰ染色体以9-10分离为主。

We used four-year old pear-jujube （ Ziziphus jujuba Mill. ） trees grafted on wild jujube[Ziziphus jujuba Mill. var. spinosa（Bunge）Hu ex H. F. Chow]to study the response of parameters derived from trunk diameter fluctuations（TDF）to soil water potential（SWP）. The relationship among these parameters and meteorological factors were also studied to identify suitable indicators for precise irrigation scheduling of pear-jujube. The maximum daily shrinkage（MDS）increased,whereas the daily growth（DG）,trunk growth rate（TGR）,and maximum daily trunk diameter（MXTD）decreased,as the SWP decreased. The responses of the four indicators to SWP change were significantly（P 0.05） different. MDS and TGR noise was lower during the stages of water stress development and water stress maintenance,whereas the ratios of signal intensity to noise were higher. MDS and TGR also had significant relationships with potential evapotranspiration（ET0）and noon vapor pressure defici（tVPDmd）, which could indicate atmospheric drought conditions. Therefore,MDS and TGR may provide appropriate indicators for diagnose pear-jujube water content.