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地膜覆盖栽培对春小麦叶片衰老特性的影响 总被引:6,自引:3,他引:6
为了揭示春小麦在地膜栽培条件下是否早衰的问题,采用管栽模拟试验的方法,研究了地膜覆盖和露地栽培条件下春小麦叶片的叶绿素、蛋白质、叶片丙二醛(M DA)含量和细胞质膜相对透性的变化。结果表明,采用地膜覆盖栽培方法,在春小麦生长前期能明显提高叶片叶绿素和蛋白质的含量(日均增加量分别比露地春小麦高31.49%和7.94%),但后期又会加速其降解速率;M DA含量和细胞质膜相对透性均表现为覆膜处理高于露地处理(日均增加量分别比露地春小麦高71.96%~11.78%和2.42%~9.57%)。说明覆膜栽培可使春小麦提前进入正常衰老阶段,但由于其增温、保湿等效应,使春小麦生长量增加,穗粒数和穗粒重比露地春小麦提高22.95%和27.68%,表现出良好的增产效应。 相似文献
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Background
Theory in ecology points out the potential link between the degree of specialisation of organisms and their responses to disturbances and suggests that this could be a key element for understanding the assembly of communities. We evaluated this question for the arable weed flora as this group has scarcely been the focus of ecological studies so far and because weeds are restricted to habitats characterised by very high degrees of disturbance. As such, weeds offer a case study to ask how specialization relates to abundance and distribution of species in relation to the varying disturbance regimes occurring in arable crops. 相似文献1000.
Changying Li Gerard W. Krewer Pingsheng Ji Harald Scherm Stanley J. Kays 《Postharvest Biology and Technology》2010,55(3):144-149
A conducting polymer gas sensor array (electronic nose) was evaluated for detecting and classifying three common postharvest diseases of blueberry fruit: gray mold caused by Botrytis cinerea, anthracnose caused by Colletotrichum gloeosporioides, and Alternaria rot caused by Alternaria sp. Samples of ripe rabbiteye blueberries (Vaccinium virgatum cv. Brightwell) were inoculated individually with one of the three pathogens or left non-inoculated, and volatiles emanating from the fruit were assessed using the gas sensor array 6–10 d after inoculation in two separate experiments. Principal component analysis of volatile profiles revealed four distinct groups corresponding to the four inoculation treatments. MANOVA, conducted on profiles from individual assessment days or from combined data, confirmed that the four treatments were significantly different (P < 0.0001). A hierarchical cluster analysis indicated two super-clusters, i.e., control cluster (non-inoculated fruit) vs. pathogen cluster (inoculated fruit). Within the pathogen cluster, fruit infected by B. cinerea and Alternaria sp. were more similar to each other than to fruit infected by C. gloeosporioides. A linear Bayesian classifier achieved 90% overall correct classification for data from experiment 1. Tenax? trapping of volatiles with short-path thermal desorption and quantification by gas chromatography–mass spectrometry was used to characterize volatile compounds emanated from the four groups of berries. Six compounds [styrene, 1-methyl-2-(1-methylethyl) benzene, eucalyptol, undecane, 5-methyl-2-(1-methylethyl)-2-cyclohexen-1-one, and thujopsene] were identified as contributing most in distinguishing differences in the volatiles emanating from the fruit due to infection. A canonical discriminant analysis model using the relative concentration of each of these compounds was developed and successfully classified the four categories of berries. This study underscores the potential feasibility of using a gas sensor array for blueberry postharvest quality assessment and fungal disease detection. 相似文献