锌营养对烟草生长及抗性生理生化指标的影响

研究了不同锌营养水平下烟草外渗电导率、可溶性糖含量、可溶性蛋白含量、游离脯氨酸含量、丙二醛含量和根系活力等相关抗性生理生化指标的变化情况。结果表明,锌浓度为0.1 mg/L处理后烟株长势较好,并且其外渗电导率、游离脯氨酸含量及丙二醛含量均低于其他处理,而可溶性糖、可溶性蛋白含量及根系活力均高于其他处理,说明该处理浓度对烟草自身抗性有明显的促进作用。

树木抗病的生理生化学研究进展

对树木受病原物侵染前后体内生化物质及其变化状况和诱发产生的多种生理生化代谢差异在寄主抗病性中作用的研究现状进行了概述。指出，目前关于树木抗病性的研究多集中在相关因素的比较分析上，有关抗病的分子机制和抗病基因定位等研究是今后深入探讨的重要方面。

棉花抗黄萎病机制及抗病性鉴定研究进展

从棉花固有的和诱发的组织结构抗性及生理生化抗性方面综述了国内外棉花抗黄萎病机制的研究现状,对棉花抗黄萎病鉴定方法进行了总结和展望。

棉花对黄萎病的抗病机制研究进展

本文概述了棉花黄萎病抗性的遗传规律和特点,从寄主与病原菌识别的相互作用、组织抗性、生理生化抗性、生态抗性4个方面综述了棉花对黄萎病抗病机制的研究进展。指出真菌诱导子是寄主与病原菌识别和互作的关键因素,不同棉株的固有组织结构抗性和诱导组织结构抗性对黄萎病的抗病表现也不相同;在生理生化抗性上重点介绍了植物抗毒素、酶、糖类物质、激素与棉花抗病性的关系;阐述了棉花对黄萎病的生态抗性,即棉花根系分泌物和根系微生物与黄萎病抗性的相互作用。在这4种抗性中,生理生化抗性起主导作用,但离不开多种抗性机制的相互作用和协调。此外,作者对棉花抗黄萎病分子育种的进展作了概述,简要介绍了RFLP、RAPD、AFLP、SSR等分子标记技术和转基因技术在分子育种中的应用与所取得的进展。最后对棉花黄萎病抗性机制及棉花抗黄萎病分子育种研究的未来发展方向和重点作了展望。

对目前棉花抗黄萎病机制的分析

据不完全统计,棉花所受病害有60余种。其中,棉花黄萎病是对棉花威胁最大的一种病害。基于此,概述棉花黄萎病的侵染特性、棉花自身的组织结构抗性和生理生化抗性,以及棉花黄萎病的相关研究进展。

猕猴桃品种对细菌性溃疡病的抗性机制

研究了安徽省猕猴桃主栽品种金魁(高抗)、早鲜(中抗)、魁蜜(抗病)、华美2号(感病)、秦美(中感)和金丰(高感)对细菌性溃疡病的抗性机制。结果表明:形态结构抗性方面,感病品种的皮孔密度和长度及气孔密度、长度和宽度都明显高于抗病品种,抗、感品种间皮孔、气孔的排列方式也存在一定差异。相关分析表明,皮孔密度和长度及气孔密度、长度和宽度与品种发病率都有较高的相关性,尤其以皮孔长度和气孔长度相关性最高,r 分别为0.9278和0.9794;生理生化抗性方面,品种未感染溃疡病菌前,芽中的 POD 酶活性与品种抗性存在规律性不强,一年生枝条、叶片中的 POD 酶活性与品种抗性有密切关系。品种感染溃疡病菌后,POD 酶活性均升高,但抗病品种中酶活提高倍数高于感病品种。一年生枝条上病斑越大,POD酶活性越高。POD 同工酶谱带表现出与酶活相一致的规律。

Effects of Water Deficit and Increased Nitrogen Application in the Late Growth Stage on Physiological Characters of Anti-aging of Leaves in Different Hybrid Rice Varieties

[Objective] This study aimed to explore the effects of water and fertilizer regulation on the function of leaves in the filling stage. [Method] Six hybrid rice vari- eties including prematurely aged types and non-prematurely aged ones were selected as experimental materials. Limiting water treatment （with soil water potential of about -25 kpa） and increasing nitrogen treatment （additional 10% of granular nitrogen fertiliz- er in addition to limiting water treatment） were applied after heading to analyse the rates of aging and physiological responses of anti-aging in different hybrid rice vari- eties under water deficit and increased nitrogen conditions taking regular water and fertilizer as control. [Result] The results showed that water deficit accelerated the leaf senescence, and prematurely aged types-＇Zhongyou838＇, ＇Tianyou998＇ and ＇Long- ping601 ＇-were more markedly affected by water deficit, of which the rates of chloro- phyll degradation were 6%-8% higher compared to that in another three hybrids. In- creasing nitrogen treatment raised chlorophyll content and slowed down its degrada- tion. Water deficit caused the increase of abscisic acid （ABA） content to obviously varying degrees in leaves of six hybried rice varieties. Responses of ABA content in six hybried rice varieties to increased nitrogen fertilizer were not consistent. Except in ＇Zhongyou838＇, ABA content in the other five hybrids had varying degrees of in- crease. The responses of the activity of antioxidant enzymes in different hybried rice varieties were inconsistent. In response to increased nitrogen fertilizer in combination with water deficit, the activity of each antioxidant enzyme changed differently. Water deficit enhanced the accumulation of malondialdehyde （MDA） in leaves of each hybrid rice. The correlation analysis showed that chlorophyll content was extremely signifi- cantly positively correlated to the resistance of each antioxidant enzyme; SOD activity in leaves also positively related to ABA content. [Conclusion] The rate of leaf aging, physiological activity of anti-aging, and response to water deficit varied in different hy- bried rice varieties. The activity of antioxidant enzymes were not all induced to improve by ABA. SOD activity can be an indicator of resistance to stress. Increasing nitrogen ap- plication significantly postponed leave senescence in the late growth stage of rice.

Effects of Hypergravity on Salt Tolerance of Wheat Seedlings

[ Objective] The study aimed to reveal the effects of hypergravity on salt tolerance of wheat seedlings. [ Method ] The seed germination rate （Gr） and germination index （Gi） of wheat seedlings were measured under hypergravity of 600 × g or 1 000 × g for 4 h and under the stress of 0.4% or 0.9% salt solution. The catalase （CAT） activity and malondialdehyde （MDA） content of wheat seedlings were also measured under 0.4% salt stress. [Result] Compared with seedlings in CK group （no hypergravity or salt stress）, the Gr and Gi of the seedlings in salt stress treatment decreased to different extents; while the Gr and Gi of the seedlings in treatment group （hypergravity and salt stress） increased compared with that in salt stress group. CAT in seedlings of hypergravity treatment was higher than that of CK group and 0.4% salt treatment group, meanwhile the MDA showed an opposite result. [ Conclusion] Hypergravity could enhance the salt resistance of wheat in specific range, and hypergravity of 600 × g for 4 h performed better than that of 1 000 ×g for 4 h.

Effects of silver nanoparticles on resistance characteristics of the wetland plant Typha orientalis in a hydroponic system

To probe the influence and the adverse-resistance characteristics of wetland plants in presence of silver nanoparticles (AgNPs), the changes in the physiological and biochemical characteristics (including the superoxide dismutase (SOD) activity, catalase (CAT) activity, peroxidase (POD) activity, soluble protein content, and chlorophyll content) of Typha orientalis exposed to different concentrations of AgNPs solutions (0, 0.1, 1, 20 and 40 mg/L) were explored. Meantime, the accumulation of silver content in these plants was revealed. The results show that under low concentrations of AgNPs, the SOD and POD activities in the leaves of Typha orientalis are strengthened to different degrees. However, high concentrations of AgNPs inhibit the activities of SOD and POD. Under the stress of different concentrations of AgNPs, the CAT activities are inhibited initially and later recovered to some extent. Under the stress of low concentrations of AgNPs, the soluble protein content in the leaves of Typha orientalis increases significantly, but decreases more significantly with increasing concentrations of AgNPs. Low concentrations of AgNPs promote chlorophyll synthesis in the leaves of Typha orientalis , but the chlorophyll content subsequently falls to pre-stress levels. In contrast, high concentrations of AgNPs cause a certain inhibition to generate chlorophyll. Meanwhile, the results show that the silver concentrations of plant tissues increase with the exposure of concentrations of AgNPs and they have a positive relationship with the exposure of concentrations of AgNPs.