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关键词： 植物   植物生理生化   植物分子生物学   植物基因工程   分子生物学实验课  

关键词： 椎实螺   水生植物   水生生物   肺螺   生物学  

摘要： 在法国利穆赞地区,作者曾采用杀螺剂CuCl;的螺亚致死的剂量结合引入小截椎实螺的有效天敌——肺螺类的Zonitoidesritidus在该地区的沼泽地进行了试验,结果一年后大部分小截椎实螺从聚集地消失。由于野外水生植物田地对该区人片吸虫病的流行有重要作用,作者用此法对该地区21个有

关键词： 紫葳科/化学  

关键词： 植物  

关键词： 植物-进化   进化-植物  

关键词： POLLINATION   LIFE HISTORY   SEED SIZE   POPULATION AGGREGATION   RARITY  

摘要： We investigated the effect of five plant and habitat characteristics on the national distribution of scar ce British plants defined as those occurring in 16-50 10 x 10 km squares ('loci'). rn all 139 species considered loci were more aggregated than expected by chance. Habitat, dispersal ability and pollination type were significantly correlated with pattern of locus distribution. Seed size and life history were unrelated to the degree of aggregation of loci. The most important result from a conservation perspective is the tendency for plants with pool dispersal ability to have more aggregated distributions (i.e. they have loci closer together) than plants with good dispersal ability. One implication of this result may be that reintroduction or translocation could be useful techniques for supplementing natural dispersal in the management of such species.

关键词： NASA Discipline Number 40-50   NASA Discipline Plant Biology   NASA Program Space Biology   Non-NASA Center  

摘要： The debate about whether gravity sensing relies upon statoliths (amyloplasts that sediment) has intensified with recent findings of gravitropism in starchless mutants and of claims of hydrostatic gravity sensing. Starch and significant plastid sedimentation are not necessary for reduced sensing in mutant roots, but plastids might function here if there were a specialized receptor for plastid mass e.g. in the ER. Alternatively, components in addition to amyloplasts might provide mass for sensing. The nucleus is dense and its position is regulated, but no direct data exist for its role in sensing. If the weight of the protoplast functioned in sensing, why would there be specific cytological specializations favoring sedimentation rather than cell mass? Gravity has multiple effects on plants in addition to gravitropism. There may be more than one mechanism of gravity sensing.

关键词： BIOLOGICAL CONTROL   WEED   LEAFY SPURGE   HOST SPECIFICITY   LIFE HISTORY  

摘要： Leafy spurge (Euphorbia esula (s.l.)) is an herbaceous perennial and serious weed of Eurasian origin that has been accidentally introduced into North America. The two European root-boring moths Chamaesphecia hungarica and Ch. astatiformis are univoltine and overwinter as mature larvae. Both species have a lower survival rate on leafy spurge than on their field hosts, and thus are not optimal candidates for the biological control of leafy spurge. However, the rate of larval development and larval growth on the target weed and on the two field hosts is nearly the same. The experimental host range of both species is restricted to a few species in the subgenus Esula within the genus Euphorbia. The two species occupy different habitats in the steppe biome and are targeted for similar leafy spurge habitats in North America.

关键词： 早春植物   生物学   生态学   草地  

摘要： 本文根据作者对阜康县农业生态站附近的早春植物在春季生长、发育节律与水、热等生态因子关系的观测,论述了它们的生物学和生态学特性,为充分利用这类植物在早春季节能够为家畜提供足够的,可利用的饲草而提出科学依据。

关键词： 病原真菌   基因表达的调控   防御体系   分子细胞生物学   时空性   葡聚糖酶   诱导抗性   植保素   信号物质   抗病机制  

摘要： 植物的抗病与病原菌的致病是生物界一种十分复杂的相互作用系统。当植物组织受到病原真菌侵染后,寄主体内的防御体系会发生一系列的改变,具有明显的时空性,且受到环境条件、代谢产物与基因表达的调控。近年来,许多研究表明,植物抗病性强弱在很大程度上决定于最初受病原真菌侵染的有限的几个细胞,即病原真菌与寄主植物直接接触的一个非常狭小的区域中。