Role of LOX3 Gene in Alleviating Adverse Effects of Drought and Pathogens in Rice

Lipoxygenase 3 (LOX3) is a major component of the LOX isozymes in mature rice seeds. To investigate the role of LOX3 gene under stresses, a plant expression vector containing antisense cDNA of LOX3 was constructed. Rice varieties Wuyunjing 7 and Kasalath were transformed by the Agrobacterium-mediated method and transgenic rice plants were generated. PCR and Southern blot results showed that the antisense LOX3 gene was integrated into the rice genome. Analyses of embryo LOX3 deletion and semi-quantitative RT-PCR confirmed the antisense suppression of LOX3 gene in transgenic plants. The T2 antisense plants of LOX3 were sensitive to drought stress, rice blast and bacterial blight compared with non-transgenic plants. These results suggest that the LOX3 gene might function in response to stresses.     

不同生长时期沙打旺不同部位及其植株的化感作用研究

研究了营养生长期、花果期、成熟期沙打旺(3年生)不同部位及其植株的化感作用.结果显示,1)不同生长时期沙打旺各个部位(如根、茎、叶)及其植株的水提液(1:60 g/mL,下同)均对受体萝卜的幼苗生长显示化感活性.表明沙打旺释放化感物质可能有多种途径(如地上部淋溶、根系分泌等).2)各个生长时期沙打旺的不同部位及其植株的水提液通常对受体植物的幼苗生长显示化感抑制作用,而且以叶的抑制作用最为显著.表明叶片是整个生长周期内集中表现沙打旺化感作用的特定部位.3)沙打旺的单一部位(地下部除外)及其完整植株的水提液在花果期的化感作用较成熟期强烈,而成熟期的化感作用强度又较营养生长期为高.表明花果期可能是沙打旺表达化感作用的关键时期.本研究对农业生产实践中沙打旺草地的管理与应用具有积极意义.     

南昌市园林植物刺蛾种类的发生及综合防治研究

刺蛾是一类重要的园林植物食叶害虫,寄主广泛,南昌市发生较为普遍。据调查,南昌市刺蛾种类有21种,危害园林植物较为严重的刺蛾种类主要有黄刺蛾Cnidocampa flavescens（Walker）、丽绿刺蛾Latoia lepida（Cramer）、褐边绿刺蛾L.consocia（Walker）、桑褐刺蛾Setor postonata（Hampson）及扁刺蛾Thosea sinensis（Walker）等5种刺蛾。本文记述了南昌市5种危害园林植物较为严重的刺蛾种类的寄主植物、发生及为害特点,以及相关的综合防治措施,为南昌市园林植物害虫防治提供参考。     

从城市生态绿地系统建设探讨园林苗木生产

城市生态绿地系统的建设需应遵循生物多样性保护、地被性植物群落保护、乡土树种保护和自然环境修复的原则。在此原则指导下,对苗木的种类、形态、功能以及引种方面提出不同的要求,并指出苗木生产的发展方向和具体措施。     

福建省棕榈科植物病害调查研究

对福建省24种主要栽培的棕榈科植物病害种类进行系统调查,采集病害标本,通过症状观察和病原鉴定,确诊了22种病害;其中,帚梗柱孢霉(Cylindrocladium sp.)叶斑病、刀孢菌(Clas-terosporium sp.)叶斑病、鱼尾葵(Caryota ochlandra)小卵孢菌(Ovularia sp)叶斑病和射盾孢菌(Actinopelte sp.)叶斑病是国内棕榈科植物新发生的4种病害;明确了华盛顿棕(Washingtonia robus-ta)镰刀菌(Fusarium spp.)立枯病等9种病害是福建省棕榈科植物发生的主要病害,为棕榈科植物病害的防治和深入研究提供了重要依据。     

孑遗植物银杏(Ginkgo biloba L.)雌雄株水分生理特征研究(英文)

[Objective] The experiment aimed to study the difference of water physiology of male and female Ginkgo biloba L. for discussing the strategy of water utilization as well as the important role of this difference during evolution process. [Method] The stem sap flow, stomatal conductance(Gs), transpiration rate(Tr) and water use efficiency (WUE) of male and female Ginkgo biloba L. were comparatively studied. [Result] The day-night processes of flow on male and female Ginkgo biloba L. were similar. The flow on male and female Ginkgo biloba L. in day were almost same while the flow at night on male Ginkgo biloba L. was bigger than that on female Ginkgo biloba L. The Tr and Gs of male and female Ginkgo biloba L. were high in morning and at night but low at noon ,while Tr and Gs of female Ginkgo biloba L. in morning and at night were higher than these of male Ginkgo biloba L. at the same time point. However, these indexes of female plant were lower than these of male plant from 11:00 to 14:00. WUE changing trends of male and female Ginkgo biloba L. were similar, while average water utilization rate of female Ginkgo biloba L. was slightly lower than that of male Ginkgo biloba L. [Conclusion] Compared with other companion plants, water physiology of male and female Ginkgo biloba L. had strong homoplasy. The phenomenon might be a survival strategy of dioecious plants under long term evolutionary pressure.     

铝对茶树叶片抗氧化系统的影响

以茶树幼苗为材料,研究不同浓度铝处理培养基(沙)下,茶树叶片抗氧化系统中保护酶活性的变化.结果表明:施铝的茶树叶片过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、愈创木酚过氧化物酶(POD)活性显著高于不施铝的,而SOD活性却显著低于不施铝的.随着供铝浓度的增大,茶树叶片SOD、APX、CAT、POD均无显著变化.说明抗氧化酶活性的变化能较好的反映出茶树缺铝状况和适量铝可以促进茶树生长的情况.     

寄主植物对三角新小卷蛾生长发育和繁殖的影响

研究不同寄主植物对三角新小卷蛾(Olethreutes leucaspis Meyrick)取食、生长、发育及存活的影响,组建三角新小卷蛾实验种群生命表.结果表明:在25℃温度下,采用荔枝、龙眼、莲雾、芒果、柑橘饲喂三角新小卷蛾的发育历期分别为20.74、18.17、23.41、23.23、29.0 d.在荔枝、龙眼上该虫幼虫和蛹的存活率较高.三角新小卷蛾在荔枝、龙眼、莲雾、芒果、柑橘上的内禀增长力(rm)分别为0.185 2、0.161 1、0.134 8、0.134 7和0.112 8.均大于0.种群趋势指数(I)分别为60.80、53.76、36.10、30.60和49.00,均大于1,该虫种群呈增长趋势.综合比较5种寄主植物,三角新小卷蛾的最适宜寄主植物是荔枝和龙眼.     

Impact of luxuriant aquatic plants on thermal convection in a closed water body

The attenuation of heat flux at the water surface with aquatic plants was examined by hydraulic experiments to consider the influence of aquatic plants on the magnitude of thermal disturbance in the closed water body. First of all, the experiment measuring temperatures on surface of leaf revealed the thermal conductivity of the leaf which is peculiar physicality of each aquatic plant. Then, the hydraulic experiment examined attenuation of the underwater illuminance and the heat flux in the covered part which depending on the kind and the luxuriant density of the aquatic plants. As the result, it is clarified that the attenuation rate of the illuminance is large in the plant with a thick leaf, and that the heat flux at the water surface and the developmental velocity of the mixed layer decreased when the luxuriant density of the aquatic plants increased.     

The effect of land management on carbon and nitrogen status in plants and soils of alpine meadows on the Tibetan plateau

Large‐scale grassland rehabilitation has been carried out on the severely degraded lands of the Tibetan plateau. The grasslands created provide a useful model for evaluating the recovery of ecosystem properties. The purposes of this research were: (1) to examine the relative influence of various rehabilitation practices on carbon and nitrogen in plants and soils in early secondary succession; and (2) to evaluate the degree to which severely degraded grassland altered plant and soil properties relative to the non‐disturbed native community. The results showed: (1) The aboveground tissue C and N content in the control were 105·97 g m⁻² and 3·356 g m⁻², respectively. The aboveground tissue C content in the mixed seed treatment, the single seed treatment, the natural recovery treatment and the severely degraded treatment was 137 per cent, 98 per cent, 49 per cent and 38 per cent, respectively, of that in the control. The corresponding aboveground tissue N content was 109 per cent, 84 per cent, 60 per cent and 47 per cent, respectively, of that in the control. (2) Root C and N content in 0–20 cm depths of the control had an average 1606 g m⁻² and 30·36 g m⁻², respectively. Root C and N content in the rehabilitation treatments were in the range of 26–36 per cent and 35–53 per cent, while those in the severely degraded treatment were only 17 per cent and 26 per cent of that in the control. (3) In the control the average soil C and N content at 0–20 cm was 11 307 g m⁻² and 846 g m⁻², respectively. Soil C content in the uppermost 20 cm in the seeded treatments, the natural recovery treatment and the severely degraded treatment was 67 per cent, 73 per cent and 57 per cent, respectively, while soil N content in the uppermost 20 cm was 72 per cent, 82 per cent and 79 per cent, respectively, of that in the control. The severely degraded land was a major C source. Restoring the severely degraded lands to perennial vegetation was an alternative approach to sequestering C in former degraded systems. N was a limiting factor in seeding grassland. It is necessary for sustainable utilization of seeding grassland to supply extra N fertilizer to the soil or to add legume species into the seed mix. Copyright © 2005 John Wiley & Sons, Ltd.