硒对月季离体叶片衰老的影响

月季叶园片经含Ｈ２ＳｅＯ３水溶液黑暗培养４ｄ表明,加Ｓｅ可降低叶园片ＭＤＡ含量,维持还原糖及Ｃｈｌ含量,降低ＰＯＤ活性。０．１￣０．５ｍｇ／Ｌ Ｓｅ使叶圆片可溶性蛋白含量及ＣＡＴ活性高于对照,０．１￣０．２ｍｇ／Ｌ Ｓｅ处理,ＳＯＤ活性较高,膜透性降低。     

FLOODING STRESS: The Effects of Planting Pattern and Water Regime on Root Morphology,Physiology and Grain Yield of Rice

Field experiments were conducted over two growing seasons to investigate the effects of variations in water regime and planting pattern on the growth of rice plant roots and shoots and on yield. Four water regimes were evaluated with split plot design: intermittent flooding during the vegetative stage only (IF‐V); intermittent flooding extending into the reproductive stage (IF‐R); not flooded (NF); and continuously flooded (CF), interacting with three different planting patterns: single seedling per hill with wider 30 × 30 cm spacing (P1); single seedling per hill with closer 20 × 20 cm spacing (P2); and three to four seedlings per hill with 20 × 20 cm spacing (P3). The treatment combination CF/P3 corresponds most closely with current conventional practice. The other combinations were evaluated to contribute to a better understanding of the effects of the two parameters studied, respectively and together. IF‐V/P1 was considered as an approximation of System of Rice Intensification (SRI) practice. This study found that the combination of singly transplanted seedlings, both P1 and P2, with the IF‐V water regime improved root length density, root physiological activity, and chlorophyll content of the upper and lower leaves, leading to higher grain yield compared with the other treatment combinations. With continuous flooding (CF), P2 gave 23 % more yield compared with the P3 planting pattern. Combining IF‐V and P2 produced 32 % more grain yield compared with the CF/P3 treatment. These results showed a synergistic effect on grain yield from reduced intra‐hill competition and IF‐V water management. In these trials, there was no significant yield difference between the IF‐V/P1 and CF/P3 treatments. Wider spacing improved the performance of individual hills when grown under IF‐V water regimes, but tiller number per unit area remained a dominant determinant of yield. The yield reduction observed for CF/P1 compared with CF/P3 indicated that in more hypoxic CF soils, denser plant populations can produce more than sparser ones, whereas the latter benefit from more aerobic soil conditions. Intermittent irrigation during the vegetative growth stage and transplanting single seedlings/hill are major elements of SRI methodology. These findings contribute to an understanding of why SRI methods can produce the higher yields reported. A consideration of the effects of interaction between planting pattern and water regime shows the need to establish empirically the optimum values for these treatments according to varietal, soil and climatic characteristics for the greatest yield response.     

不同基因型抗虫棉的光合生产与叶源特征

以33B为对照,对早发型常规Bt棉鲁棉研17、鲁棉研21,晚发型Bt棉鲁棉研22,杂交Bt棉鲁棉研15、鲁棉研20进行了2年的种植和比较。早发型品种中前期干物质积累和叶面积增长快,但后期干物质积累慢、叶面积下降快,表现出明显的早发早熟和干旱年份易早衰的特点;晚发型品种前期干物质积累和叶面积增长慢,但后期增长快,表现出明显的晚发甚至贪青晚熟的特点。两个杂交棉品种表现出与早发型品种基本相同的生育规律,但中前期叶面积系数和干物质积累量显著高于其它供试品种。盛铃期以前,未见品种间功能叶光合速率的显著差异,但在干旱年份,早发型品种在始絮期功能叶的光合速率显著低于晚发型品种。早发型品种中后期的根冠比和功能叶含K量显著低于晚发型品种,而叶面积载荷量却显著高于晚发型品种。不同品种干物质产量和熟相的差异可能分别与叶面积系数大小和库源比例不同有关。     

深松和翻耕对旱地小麦花后根系衰老及产量的影响

为了解深松耕作对小麦根系衰老及产量的影响,以济麦22为材料,通过田间试验,对深松与翻耕条件下旱地小麦花后根系部分生理指标以及籽粒产量进行了比较分析。结果表明,与翻耕处理相比,深松处理小麦花后根系能够保持较高的超氧化物歧化酶活性与硝酸还原酶活性,丙二醛含量较低,可溶性蛋白含量降低缓慢,说明深松处理能够减缓根系的衰老。深松处理的小麦穗数、穗粒数、千粒重高于翻耕处理,其中穗粒数增加达到显著水平,是深松处理增产的主要原因。     

水杨酸对离体青稞叶片衰老的缓解效应

以青稞幼苗离体叶片为试材,在暗培养条件下,研究了水杨酸处理对离体青稞叶片叶绿素总量、丙二醛(MDA)、脯氨酸、可溶性蛋白质含量的影响。结果显示,在离体青稞叶片衰老过程中,叶绿素总量和可溶性蛋白质含量均不断下降,MDA和脯氨酸含量升高。用800 mg/L的水杨酸处理可延缓离体青稞叶片叶绿素总量和可溶性蛋白质含量的降低,抑制MDA、脯氨酸含量的上升。表明水杨酸降低了离体青稞叶片膜脂过氧化程度,延缓了离体青稞叶片衰老的进程。     

干旱胁迫对番茄活性氧代谢的影响

干旱胁迫导致番茄叶片ＲＷＣ、Ｃｈｌ和可溶性蛋白质含量下降，质膜透性和ＡＴＰａｓｅ活性提高．短期干旱胁迫可提高叶片ＳＯＤ和ＣＡＴ活性．４ｄ以内的干旱胁迫后复水，ＲＷＣ、Ｃｈｌ和可溶性蛋白质含量升高，清除活性氧保护酶ＳＯＤ、ＰＯＤ和ＣＡＴ的活性显著提高，抗氧化物质ＡｓＡ和ＧＳＨ的水平得到恢复，ＭＤＡ得到清除，自动氧化速率降低，重新建立了活性氧产生与清除的平衡系统，ＡＴＰａｓｅ活性降低，膜系统的损伤得到修复，透性降低，恢复了原有正常的生理代谢机能．长期干旱胁迫导致叶片清除活性氧的平衡体系受到破坏，ＳＯＤ、ＰＯＤ和ＣＡＴ活性以及ＡｓＡ和ＧＳＨ的含量下降，膜脂过氧化加剧，自动氧化速率提高，ＭＤＡ积累，影响番茄正常代谢，从而加速衰老进程     

不同杂交稻灌浆期叶片衰老指标在常规水分管理及限水条件下的变化趋势(英文)

[目的]为了探讨杂交稻叶片衰老的表现型,为水稻抗早衰栽培技术和抗早衰新品种选育提供依据。[方法]本文选用6个杂交稻组合,在抽穗后常规水分管理和限水条件下,研究根系活力、叶片氮素含量、叶绿素含量、净光合速率、以及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性动态及其对水分亏缺的响应。[结果]不同杂交稻品种的根系伤流强度、叶片氮素含量、叶绿素含量和净光合速率的衰减节律有明显差异,表现在衰减的起始时间、频率和衰减量。不同组合各生理指标对水分亏缺的响应不完全一致。叶绿素含量衰减率与根系活力和叶片氮含量衰减率呈极显著正相关关系;净光合速率与叶绿素含量呈极显著正相关关系。SOD、CAT和POD活性动态不同,不同组合对水分亏缺的响应不同。叶绿素含量、叶片氮素含量的变化动态与SOD和CAT活性呈极显著正相关关系;叶绿素含量、叶片氮素含量的变化动态与丙二醛(MDA)含量呈极显著负相关关系。不同杂交稻组合叶片生理指标的衰减节律及其对水分亏缺响应存在基因型差异;提高根系活力和叶片抗氧化保护酶活性,利于延缓叶片氮素含量和叶绿素含量的衰减、维持叶片较高的光合功能。[结论]水稻的抗衰老特性是基因型差异及其各项生理机能对环境应答结果。     

钙对延缓杂交水稻叶片衰老的作用机理

以叶绿素、蛋白质含量为衰老的生理指标，研究了不同ｐＨ、Ｃａ２＋对杂交水稻叶片衰老的作用。结果表明，不同ｐＨ影响叶绿素和蛋白质含量，最适ｐＨ为６．０；此条件下的Ｃａ２＋浓度为０．０１～２０．００ｍｍｏｌ／ｌ，低浓度的Ｃａ２＋提高叶片中叶绿素和蛋白质含量，提高超氧化物歧化酶（ＳＯＤ）、过氧化氢酶（ＣＡＴ）、过氧化物酶（ＰＯＤ）活性，降低丙二醛（ＭＤＡ）含量；随着Ｃａ２＋浓度升高，则作用减弱；最适浓度为０．１ｍｍｏｌ／ｌ。Ｃａ２＋能延缓杂交水稻叶片的衰老，主要原因是由于Ｃａ２＋能提高叶片中活性氧防御酶的活性，降低活性氧的伤害作用。     

适用于表征古树衰老的生理指标

随着古树的衰老,代谢水平逐渐下降,多种酶趋于降解,营养物质合成速率降低,叶绿体和线粒体活力降低,明显出现器官水平上的程序化细胞死亡。本文概述近20年来国内外对古树叶片超微结构、叶绿素含量、蛋白质含量、活性氧防御系统、矿质营养元素等生理指标的检测和分析结果,旨在对古树的衰老检测和复壮提供理论依据和切实可行的方法。     

檫木叶片秋季衰老时叶色、色素和营养元素的关系

【目的】从叶片衰老角度研究檫木叶片叶色、色素和营养元素的变化规律,为秋色叶观赏树种檫木的选育以及栽培提供理论依据。【方法】以栽植于同一环境条件下的3年生檫木为试验材料,从檫木叶片停止生长到脱落,分5个时期对叶片的叶色值、色素含量和营养元素含量进行观测和分析。【结果】观测前期与观测后期,檫木叶片叶色值、色素含量和营养元素含量存在极显著差异;叶片进入衰老阶段后,叶绿素含量和类胡萝卜素含量呈下降趋势,而花色素苷含量逐渐上升;N、P、K含量在叶片衰老阶段逐渐下降。由典型相关分析可知,叶色a*值与叶绿素含量具有显著负相关,与花色素苷含量呈显著正相关;花色素苷含量与N含量成反比,类胡萝卜素含量与P含量成正比;N元素再利用效率的载荷值符号与N含量载荷值的符号相反,而P元素再利用效率的载荷值符号与P含量载荷值的符号相同;檫木叶片衰老分为3个阶段,第1阶段从9月中下旬到10月上旬,为叶片衰老准备期;第2阶段从10月中下旬到11月上旬,为叶片缓慢衰老期;第3阶段从11月中下旬到叶片脱落,为叶片衰老末期。【结论】檫木叶色最佳观赏期是从10月中下旬到11月上旬的叶片缓慢衰老期;从叶片衰老准备期到叶片衰老末期,叶绿素和类胡萝卜素被分解,花色素苷合成;N、P、K 3种营养元素逐渐被转移,其中N含量越高,N元素再利用效率就越低;与之相反,P含量越高,P元素再利用效率就越高。