光对花生叶片绿色细胞糖酵解代谢的影响

光下花生叶肉细胞悬浮液暗呼吸只有暗中的18％左右,丙酮酸含量下降,细胞质磷酸丙糖积累,叶绿体3—磷酸甘油醛脱氢酶活性上升,而非叶绿体的酶活性下降,叶绿体和细胞质的ATP/ADP比值同时增加。ATP/ADP>1时离体细胞质3—磷酸甘油醛脱氢酶活性下降,但叶绿体的酶不受影响。表明光下ATP/ADP比值上升影响细胞质3—磷酸甘油醛脱氢酶活性而使糖酵解受抑制。     

18年生杉木不同部位和叶龄针叶光响应研究

在最适温度(30±1℃)、适宜湿度(70%±5％)和正常大气CO2浓度（350±10×10-6V/V）向下,采用活体测定方法,测定了18年生杉木不同部位和叶龄针叶对光照的稳态和动态响应。结果表明,不同部位和叶龄针叶净光合速率（Pn）的光响应特征有明显差异,从上部到下部、从当年生到1年生至2年生,针叶Pn、饱和光强（PSLI）和光补偿点（LCP）降低,表观量子效率（α）提高。经一定时间暗处理后,针叶需要一定光诱导才能获得相应光强下的最大Pn。光诱导期长短与猝发性光强以及叶龄和针叶在树冠中所处的部位有关。猝发性光照越强,所需的光诱导期越长;下部针叶光诱导期短于中部针叶;而1年生针叶短于当年生针叶。不同部位针叶对稳态和动态光照的响应与针叶长期适应所处的光环境有关,而不同叶龄的差异除与生理活性有关外,也可能与所处的光环境有关。     

BA对花生叶片蔗糖和淀粉代谢有关酶活性的影响

用１０－５ｍｏｌ／ＬＢＡ处理去顶去根花生幼苗库叶２４ｈ内．蔗糖磷酸合成酶和细胞质果糖－１,６－二磷酸酯酶活性逐渐增加．酸性转化酶活性降低．使蔗糖含量提高,α－淀粉酶活性的增强,促进淀粉分解。ＢＡ处理２４ｈ后,随着蔗糖磷酸合成酶和细胞质果糖－１．６－二磷酸酯酶活性的减弱．酸性转化酶活性逐渐增加．蔗糖含量减少,有利光合碳在淀粉的积累．     

羊草不同叶龄叶片光－光合特性的初步研究

在6月至7月,羊草叶片在充分展开后的数天之内,即最上展开叶,其净光合速率及其光强系数,以及光饱和点,近饱和点和半饱和点最高;幼龄叶和老龄叶的上述各项指标均较低,但随着光强的下降,不同叶龄叶片的净光合速率或光合的光强系数的差别均逐渐减小,光补偿点以半展开幼叶较低,而后随叶龄增长逐渐升高,羊草的壮龄叶对光的利用能力较强,在其光合生产中起主要作用,幼龄叶仅对弱光的利用能力高,老龄叶相对地较为耐阴。     

BA对花生叶片腺苷酸含量和能荷的影响

去顶去根花生幼苗库叶（上位叶）经１０＾－５ｍｏｌ／Ｌ ＢＡ涂抹处理１２ｈ和４８ｈ时,库叶ＡＴＰ含量增加,分别高于对照１９．４％和３３．１％。ＡＤＰ含量在处理后１２－３６ｈ,不断增加,以后逐渐降低,接近对照水平,ＢＡ处理库叶减少ＡＭＰ含理。ＢＡ促进库叶能荷值增加,调节总腺苷酸含量的动态变化。ＢＡ处理库叶１２ｈ,叶片组织和线粒体呼吸速率增加,加强了线粒体氧化磷酸化和能量传递的过程。     

光质对花生幼苗叶片光合色素含量及光合特性的影响

在单色LED灯光照条件下,以青花6号花生品种为材料,研究了不同光质对花生幼苗光合色素含量及光合特性的影响.结果表明:与自然光照相比,蓝光(445~470 nm)可显著提高花生幼苗比叶面积、叶绿素a/b值和类胡萝卜素含量,净光合速率、气孔导度、蒸腾速率较高,胞间CO2浓度较低,光合效率显著提高;红光(610~660 nm)显著提高了叶片叶绿素含量,降低了比叶面积、叶绿素a/b值和类胡萝卜素含量,光合效率低于自然光照;绿光(515~520 nm)和黄光(590~595 nm)不利于光合色素的积累,显著抑制了花生幼苗叶片的光合作用.     

对采用平均叶龄估算叶年净初级生产量的修正

根据森林和林木各器官生物量随时间的变化,林冠叶片（叶群体）生长和死亡规律及数学生态学的原理,得出了叶的生物量,年净生产量和平均叶龄之间的关系。一般表达式为Ｐ＝│１ｎｌｘ│·Ｂ／ｘ（式中Ｐｎ为叶年净生产量,ｌｘ为特定叶龄的存留率,Ｂ为叶生物量,ｘ为平均叶龄）。当林冠叶片达到平衡时,Ｐｎ＝０．６９３·Ｂ／ｘ;存留率为３６．８％,成为目前用平均叶龄计算叶年净初级生产量的形式。本文证明了后一种特殊形式之所     

钙对花生叶片糖代谢有关酶活性的影响

5mmol／Lca2抑制花生叶片果糖-1,6-二磷酸酯酶、磷酸烯醇式丙酮酸羧化酶、磷酸烯醇式丙酮酸磷酸酯酶、丙酮酸激酶和NADP-磷酸甘油醛脱氢酶活性。以含0、5、15mmol/LCa2 的Hoagland营养液培养花生幼苗,在5mmol/LCa2 条件下,果糖-1,6二磷酸酯酶和磷酸烯醇式丙酮酸羧化酶活性最高,0、15mmol／LCa2 均使酶活性降低,光合速率亦呈现相同变化趋势。丙酮酸激酶活性在缺Ca2 时最高,与呼吸速率变化相同。15mmol/LCa2 提高了叶绿素含量。     

水分对番茄不同叶龄叶片光合作用的影响

以番茄品种"金棚1号"为材料,采用盆栽方式,按照蒸腾蒸发量(ET)的50%、75%、100%和125%作为补充灌溉量研究了不同水分下番茄结果期叶片气体交换特性和光响应特征参数随叶龄的变化。结果表明:番茄叶片随着叶龄的增加,净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)逐渐降低,水分利用效率(WUE)呈先上升后下降趋势;叶龄为18 d和29 d的叶片最大净光合速率(Pmax)随灌溉量的增加均先增加后降低,分别在75%ET和100%ET处理达到最大值。叶龄为38 d和47 d的叶片Pmax均以125%ET处理最大。表观量子效率(α)随叶龄的增大也先升高后下降,在叶龄为38 d时最大;番茄叶片的光饱和点(LSP)随叶龄的加大而减小。不同水分处理下不同叶龄叶片的光响应特征参数为:叶片在叶龄为18 d时,Pmax为20.64—26.73μmol.m-.2s-1,α为0.0518—0.0556;叶龄为29 d时,Pmax为11.00—24.24μmol.m-.2s-1,α为0.0522—0.0594;叶龄为38 d时,Pmax为11.77—18.18μmol.m-.2s-1,α为0.0619—0.0693;叶龄为47 d时,Pmax为9.09—18.17μmol.m-.2s-1,α为0.0538—0.0606。随叶龄加大,增加补充灌溉量有利于延缓叶片光合能力的降低。气孔限制是水分影响番茄叶片光合作用的主要因素,气孔限制与非气孔限制因素是番茄叶片Pn随叶龄变化的原因。     

苗期遮荫对花生（Arachis hypogaea L.）光合生理特性的影响

大田条件下,以花生品种"花育22号"为材料,齐苗期设置遮荫50%和85%两个遮荫强度分别处理40d,研究了遮荫对花生光合特性的影响及遮荫解除后的光合恢复规律.结果表明:(1)与正常光照条件相比,遮荫花生叶片净光合速率(Pn)、RuBP羧化效率降低,叶绿素含量、表观量子效率及光系统Ⅱ的最大光化学效率(Fv/Fm)增加,表明花生对弱光胁迫有一定的自我调节和适应能力.(2)遮荫和自然光下生长的花生中午强光下的Fv/Fm值均明显下降,表明发生了光抑制,遮荫程度越大,光抑制愈严重.(3)Fv/Fm值和净光合速率Pn遮荫解除后5d之内持续下降,之后逐步恢复.遮荫50%处理的叶片Fv/Fm值和Pn分别于遮荫解除后8d和10d左右恢复到对照水平;遮荫85%的处理分别于遮荫解除后15d和20d左右才恢复到最大,但Pn不能恢复到对照水平,显著低于对照.     

花生转基因研究进展

花生是世界上重要的油料和经济作物之一,是人们生活的植物脂肪和蛋白质来源。现代生物技术的不断发展为花生育种和种质创新提供了新的技术手段, 它可以直接将来自不同种属的异源目的基因插人到花生基因组, 使花生表达目标性状, 实现花生品种的遗传改良。近年来, 国内外花生转基因研究取得了重大进展。文章综述了花生转基因在抗虫、抗病、抗非生物逆境和品质改良等方面的最新进展,并总结了近年来人们对农杆菌介导法、基因枪法和不依赖组织培养的转化法等主要的花生遗传转化方法的改进和探索。     

Light, dark and growth regulator involvement in groundnut (Arachis hypogaea L.) pod development

Gynophore elongation and pod formation were studied in peanut plants (Arachis hypogaea L.) under light and dark conditions in vivo. The gynophores elongated until pod formation was initiated. Pod (3–20 mm length) development could be totally controlled by alternating dark (switched on) and light (switched off) conditions, repeatedly. Gynophore elongation responded conversely to light/dark conditions, compared to pods. In this study we aimed to correlate the light/dark effects with endogenous growth substances. The levels of endogenous growth substances were determined in the different stags of pod development. Gynophores shortly after penetration into the soil, white gynophores, released twice the amount of ethylene as compared to the aerial green ones, or to gynophores bearing pods. Ethylene inhibitors had no effect on the percent of gynophores that developed pods, but affected pod size which were smaller compared to the control. A similar level of IAA was extracted from gynophore tips of green gynophores, white gynophores and pods. ABA levels differed between the three stages and were highest in the green gynophores and lowest in the pods.Abbreviations ABA abscisic acid - AOA aminooxyacetic acid - ELISA enzyme linked immunosorbent assay - Ethrel 2-chloroethanephosphonic acid - GC gas chromatography - HPLC High Performance Liquid Chromatography - IAA indole-3-acetic acid - NAA naphthalene acetic acid - RIA radioimmunoassay - STS silver thiosulfhate - TIBA 2,3,6-triiodobenzoic acid     

花生叶片离体培养花器官分化及其开花结果研究

以花生幼叶为外植体进行离体培养,研究BA浓度对花器官分化的影响并进一步观察试管内花器官的发育.结果表明:经MSB 1mg/LBA 0.5mg/LKIN 2mg/LIAA培养基诱导的愈伤组织,转接到附加1～3mg/LBA的MSB培养基上培养,均能直接诱导分化花器官,但2mg/LBA的诱导效率最高达21.13%;诱导分化的花器官转接到MSB培养基继续培养,部分花器官可以在试管内开花、受精、成针、结实.试验实现了以花生幼叶为外植体,在试管内完成诱导花芽、开花、受精、形成果针、子房膨大,直至形成荚果等过程,为离体条件下研究花生花器官分化、荚果及种子发育提供了技术体系和材料.     

Genetic Diversity of Rhizobia Nodulating Arachis hypogaea L. in Central Argentinean Soils

The diversity of thirty-nine isolates from peanut plants growing at fourteen different sites in the Argentinean province of Córdoba was examined by rep-PCR, RFLP of PCR amplified 16S rRNA gene and complete sequencing of ribosomal genes. The genomic analysis of the peanut isolates indicated that each group encompasses heterogeneity among their members, having distinct rep fingerprints and 16S rRNA alleles. Complete sequencing of 16S rRNA demonstrated that native peanut rhizobia from Córdoba soils representative of the slow and fast growers are phylogenetically related to Bradyrhizobium japonicum and Bradyrhizobium sp. and Rhizobium giardinii and R. tropici species, respectively. The nodC gene sequence analysis showed phylogenetic similarity between fast grower peanut symbionts and Rhizobium tropici.     

Partial decline of Arachis hypogaea L. photosynthesis triggered by drought stress

Photosynthetic capacity (PC) of three peanut cultivars (Arachis hypogaea L. cvs. 57-422, 73-30, and GC 8-35) decreased during drought stress (decline in relative water content from ca. 95 to 70 %) and recovered two days after rewatering. Mild water stress was not limiting for the total ribulose-1,5-bisphosphate carboxylase/oxygenase activity, since this enzyme activity increased under drought. Photosystem (PS) 2 and PS1 (the latter only in cv. GC 8-35) electron transport activities decreased under drought. The ratio of the variable to maximal chlorophyll fluorescence (Fv/Fm) decreased mainly in the cv. GC 8-35. All cultivars showed decreases in photochemical quenching (qP) and quantum yield of PS2 electron transport (Φe). Increase of basal fluorescence (F0) was observed in the cvs. 73-30 and GC 8-35, while the cv 57-422 showed a decrease. After rewatering a sharp increase was observed in the majority of the parameters. Thus under the present stress conditions, the cv GC 8-35 was the most affected for all the parameters under study. The cv. 57-422 showed a higher degree of tolerance being gradually affected in photosynthetic capacity (PC) in contrast to the two other cvs. which showed a sharp decrease in PC at the beginning of the drought cycle. This revised version was published online in September 2006 with corrections to the Cover Date.     

花生衰老进程的研究

通过对鲁花11号和辐8707 2个高产花生品种的衰老进程研究表明：花生衰老具有地上部（叶片）渐进衰老和整株衰老的双重特点。花生从始花至花后60d左右为地上部（叶片）渐进衰老期：此期主茎高、侧枝长、分枝数、主茎、侧枝绿叶数、叶面积、茎、叶干重迅速增加,并接近或达到最大值,主茎及侧枝基部叶片逐渐由下向上开始衰老死亡,饱果开始出现,根系活力、固氮酶活性逐渐升高至接近最大值,始花后60－90d为整株缓衰期,此期地上部茎叶生长基因停止,逐渐开始衰老死亡,主茎、侧枝绿叶数开始减少,生殖体（荚果）干重迅速增长,根系活力、固氮酶活性缓慢降低;始花后90d以后称为整株速衰期,此期主茎、侧枝绿叶迅速减少,地上部迅速衰老死亡,生殖体（荚果）干重缓慢增长,根系活力、固氮酶活性迅速降低。地上部（叶片）渐进衰老期与开花及大量荚果形成相对应,整株缓衰期伴随着荚果迅速增重,整株速衰期与荚果缓慢增重一致。     

Characterization of isoperoxidase activity in Arachis hypogaea cultivars

Isoperoxidases (both anodic and cathodic) from individual seeds of several peanut cultivars (Arachis hypogaea), after ammonium sulfate precipitation of the major storage protein, arachin, from the extracts were characterized by polyacrylamide gel electrophoresis with respect to seed development, maturity and germination and the geographic areas where grown. All cultivars had a major cathodic isozyme near the origin of the gels. Much anodic intra- and inter-varietal isozyme polymorphism was observed in mature seeds collected from different geographic areas. These polymorphic isozymes were consistently present during the earlier stages of seed development (the activities decreased quantitatively and became variable during the later stages of maturation), and most were observed in each peanut upon germination, the latter showing quantitative increases in activity.