Daily and seasonal CO2 exchange in Scots pine grown under elevated O3 and CO2: experiment and simulation

Starting in early spring of 1994, naturally regenerated, 30-year-old Scots pine (Pinus sylvestris L.) trees were grown in open-top chambers and exposed in situ to doubled ambient O₃,doubled ambient CO₂ and a combination of O₃ and CO₂ from 15 April to 15 September. To investigate daily and seasonal responses of CO₂ exchange to elevated O₃ and CO₂, the CO₂ exchange of shoots was measured continuously by an automatic system for measuring gas exchange during the course of one year (from 1 Januray to 31 December 1996). A process-based model of shoot photosynthesis was constructed to quantify modifications in the intrinsic capacity of photosynthesis and stomatal conductance by simulating the daily CO₂ exchange data from the field. Results showed that on most days of the year the model simulated well the daily course of shoot photosynthesis. Elevated O₃ significantly decreased photosynthetic capacity and stomatal conductance during the whole photosynthetic period. Elevated O₃ also led to a delay in onset of photosynthetic recovery in early spring and an increase in the sensitivity of photosynthesis to environmental stress conditions. The combination of elevated O₃ and CO₂ had an effect on photosynthesis and stomatal conductance similar to that of elevated O₃ alone, but significantly reduced the O₃-induced depression of photosynthesis. Elevated CO₂ significantly increased the photosynthetic capacity of Scots pine during the main growing season but slightly decreased it in early spring and late autumn. The model calculation showed that, compared to the control treatment, elevated O₃ alone and the combination of elevated O₃ and CO₂ decreased the annual total of net photosynthesis per unit leaf area by 55% and 38%, respectively. Elevated CO₂ increased the annual total of net photosynthesis by 13%.     

增强UV-B辐射对蚕豆叶片微粒体膜一些性质的影响

温室条件下,用0（Control）、8．65kJm－2d－1（TI）及11．2KJm－2d－1（t2）不同剂量的UV－B辐射处理蚕豆幼苗。Ca2 ．ATPase及Mg2 －ATPase的活性在辐射处理期间下降。在处理21d,T1和T2微粒体膜的MDA含量明显高于对照,同时IUFA急剧下降,且呈明显的剂量效应。14及21d时,膜磷脂的含量也明显下降。脂氧合酶（Lox）活性在第7及14天与对照相比都显著升高,而21d后迅速下降。结果表明,增强UV－B对微粒体膜的伤害可能是一方面导致正常酶合成与分解之间的平衡失调,另一方面导致了膜脂过氧化作用。     

外源钙调素和钙调素拮抗剂对烟草离体花粉管生长和生殖核分裂的调节

外源花椰菜钙调素（CaM）、牛脑CaMagarose以及CaM拮抗剂TFP对花粉管生长与生殖核分裂的作用均具有浓度和时间效应,CaM在花粉管生长早期,较低浓度能促进花粉管生长和生殖核分裂;但后期,较高浓度则有抑制作用。ITP在花粉管生长早0000000000000期,较高浓度抑制花粉管生长和生殖核分裂。     

沙枣花蜜腺的发育解剖学研究

沙枣的花蜜腺位于花柱基部的筒状花盘上,属花盘蜜腺,其蜜腺位于花盘外方,由分履表皮和产蜜组织组成。分泌表皮具有角质层和变态的气孔器。产蜜组织在发育过程中,其液泡和淀粉粒都随着蜜腺的发育呈现一定的消长规律,最后形成的蜜汁由盘状蜜腺表面的气孔泌出。     

植物微核技术在监测水质污染中的应用

应用韭菜微核技术,检测哈尔滨市量具刃具厂含铬废水的遗传毒性,试验表明：含铬废水可诱导韭菜和蚕豆根尖细胞产生微核,进行回归分析,其蚕豆对Ｃｒ＾＋６诱变剂回归分析为ｙ＝２４．９４＋１２７．７７ｘ（ｒ＝０．９９６,Ｐ〈０．０１）,韭菜对Ｃｒ＾＋６诱变剂回归广泛为：ｙ＝２１．７４＋１００．２３ｘ（ｒ＝０．９００,Ｐ〈０．０１）,ｒ＝１１．１７＋３．３８ｘ（ｒ＝０．７８１,Ｐ〈０．０５）,韭菜根尖微核技术具     

火炬松(Pinus taeda L.)合子胚愈伤组织的器官发生和植株再生

以火炬松(Pinus taeda L.)的成熟合子胚为外植体在附加NAA和BA的TE培养基上诱导产生了淡黄色、疏松、有光泽的颗粒状愈伤组织。经过愈伤组织的保持和增殖培养及不定芽原基的诱导培养后,进行了不同激素、低温处理和蔗糖浓度对不定芽分化的影响实验。结果表明,在附加0.5 mg·L~(-1)IBA和2 mg·L~(-1)BA的TE培养基上,愈伤组织上的不定芽分化频率最高达62.15%。不定芽分化的最佳低温处理时间是5—6周,最佳蔗糖浓度是25—30 g·L~(-1)。不定芽经伸长培养后取高于1cm的小苗用于生根。在附加IBA、BA和GA_3的TE培养基上不定芽的生很频率最高达46%。     

In vitro stem elongation of sweet pepper in media containing 24-epi-brassinolide

In vitro regeneration of sweet pepper (Capsicum annuum L. cvs Jupiter and Pimiento Perfection) has been performed via direct organogenesis. The resulting shoot-buds were placed on media containing 24-epi-brassinolide (EBR) 0.1 μM, a plant steroid lactone, in the presence or absence of zeatin 9.1 μM plus GA3 5.2 μM for further stem elongation. Different responses to these treatments were recorded depending upon the protocols used and the genotypes tested. It appears that EBR does not always act directly on stem elongation but may be an elicitor and/or an enhancer of elongation in concert with endogenous and other exogenously added growth regulators. Elongated shoots were easily rooted with alpha-naphtalenacetic acid 0.5 μM (0.1 mgl-1) and transfered to soil, and following acclimation were taken to maturity in the greenhouse. This revised version was published online in June 2006 with corrections to the Cover Date.     

陆地棉枯萎病抗性基因的等位性测定及连锁分析

1995-1996年,对我国育成的有代表性的5个抗病品种进行抗枯萎病基因的等位性测定。结果表明:在所选用的5个抗病品种中至少存在两个不同的抗病基因(暂定名为Fwl和Fw2)。连锁分析显示:Fwl与T586的8个标志性状间、Fw2与T582、T586的13个标志性状间无连锁关系。 Abstract:Allelism in vestigation of genes resistante to Fusarium wilt in cotton suggested that there were 2 genes(assigned symbols Fw1 and Fw2)in 5 cultivars used.No linkage was found between Fw1 and the marker genes in T586 and between Fw2 and those marker genes in T582 and T586.