大豆叶片衰老QTL的初步定位

 【目的】叶片衰老是植物的一个发育性状，对植物体内营养再分配与光合作用有重要影响。【方法】利用2套重组自交系群体进行大豆叶片衰老QTL的初步定位，并进行与产量性状的相关分析。【结果】在C1、D1b+W和O连锁群上检测到3个与大豆叶片衰老有关的QTL，可解释表型变异的5.8%～13.7%。除NJ(SP)BN群体熟期与叶片衰老相关程度较低外，两个RIL群体中生物学产量、籽粒产量、株高和熟期与叶片衰老间均存在显著或极显著的正相关；而收获指数与叶片衰老间一个群体为极显著负相关，另一个群体则表现为极显著正相关。【结论】在大豆育种中，针对延迟叶片衰老选育出的材料有时仅能提高收获指数，这样的材料往往产量潜力不高。     

果树叶面积简易测定方法研究

近１０余年来,人们对果树叶面积简易测定方法进行了大量研究,涉及苹果、梨、葡萄、西瓜、桃、李、杏、柿、猕猴桃、石榴、山楂、枣、板栗、黑穗醋栗、核桃等果树。本文从单叶面积、枝条叶面积和单株叶面积等３个方面对其进行了简要评述,并对有关问题进行了讨论和分析。     

大豆生态研究──Ⅶ．光温综合作用与野生大豆（G．Soja）生殖生长关系的研究

野生大豆（Ｇ．Ｓｏｊａ）在原产地自然光温条件下，正常期出苗，营养和生殖生长阶段，气温升高，叶片感光效应反应促进营养生长．气温下降，叶片感光效应反应抑制营养生长而促进本节生殖生长．展开叶感光效应发生初生花序，定形时感光效应发生次生花序．还提出了光温综合作用与花荚形成的过程．     

水稻氮素供需差与不同叶位叶片氮转运和衰老的关系

 采用去穗和疏花方法调节稻穗氮需求量 ,研究了水稻氮素供需差 (NSDB)对不同叶位叶片氮转运和衰老的影响。结果表明 ,在NSDB <0的条件下 (对照 ) ,植株上部 4张叶输出氮素 ,叶片正常衰老 ;随NSDB提高 ,顶部叶片尤其是顶 4叶的氮素输出显著减少 ,叶片MDA含量下降 ,SOD和CAT酶活力提高 ,上位叶与下位叶之间的叶色差缩小 ;当NSDB >0以后 (去穗 ) ,上部 4叶的氮积累量不仅未减少 ,相反还有显著的增加 ,叶片的衰老进程被延缓。研究证实顶 4叶叶色受氮素供需差的影响最大 ,当土壤供氮不能满足库需氮时 ,顶 4叶叶色浅于顶 3叶     

6种番茄叶表皮制片方法比较

结合番茄叶片结构特点,采用6种表皮制片技术对番茄叶片下表皮进行装片,并对不同方法的制片过程和观察效果进行比较研究.结果表明,番茄叶片薄,表皮为单层细胞,其上着生有丰富表皮毛,下表皮与疏松的海绵组织相邻;表皮撕取法和透明胶带粘取法可以真实地观测气孔大小、密度等静态性状指标和气孔开度等动态行为;因番茄叶柔软,刮片法对操作要...     

悬铃木叶片再生体系的建立

以悬铃木为试验材料 ,系统地研究了激素浓度、叶片生理状态、光照条件等诸多因素对叶片再生的影响 ,建立了悬铃木叶片外植体的不定芽高频再生体系。研究结果表明 ,以顶部充分伸展的 4 0d叶龄的无菌苗叶片为外植体 ,再生效果最好 ,将此类叶片放在含 1 5mg·L- 1 6 -BA ,0 5mg·L- 1 IBA和 0 5mg·L- 1 KT的MS分化培养基上 ,暗培养 7d后转到光下培养 ,15d后便可见到不定芽不经过或经过很少的愈伤组织阶段 ,直接从叶片上分化产生 ,出现的高峰期在接种后的 2 0～ 30d ,芽分化率高达 98%以上。待小芽长至 1～ 2cm ,将其从叶片上切下 ,转到芽伸长培养基 (MS 0 3mg·L- 1 6 -BA 0 0 5mg·L- 1 NAA 30mg·L- 1 Ad)上使小芽长大成苗 ,最后移到生根培养基(1 2MS 0 1mg·L - 1NAA)上 ,最终得到完整的植株。该再生体系可作为基因转化的受体系统。     

Effects of N, NP, and NPKS fertilizers applied to four-year old hybrid poplar plantations

Mineral fertilizers were applied to adjacent plantations of 2, 4-year old, hybrid poplars: clone 27 (Northwest, P. deltoides × P. balsamifera) and 794 (Brooks, P. deltoides × P. × petrowskyana), in north eastern Alberta. Fertilization was done in May 2003 to see whether growth rates could be increased and rotations shortened. Three fertilizers (N, NP and NPKS + Cu + Zn) were applied at each of three rates (supplying N at 0, 100 and 200 kg ha⁻¹) in a factorial randomized block design to the two separate plantations. Fertilization with 200 kg ha⁻¹ N and 100 kg ha⁻¹ P increased volume growth of clone 27 by 1 m³ ha⁻¹ year⁻¹ over 2 years. Clone 794 showed no volume response to fertilization, but produced 8.7 m³ ha⁻¹ more than clone 27. Leaf area, dry mass and nutrient concentrations of both clones increased in the first year after fertilization, showing that fertilizer uptake occurred. Decrease in leaf size between 2003 and 2004 was affected by fertilizer level in clone 794. There were differences between some nutrient concentrations in the soils occupied by the two clones, and clone 794 had higher leaf concentrations of N, K, Ca, S, Mn, Zn, B and Mo than clone 27. Fertilization of 4-year old plantations of either clone was unwarranted, and planting clone 794 would be likely to provide greater yield than planting and fertilizing clone 27.     

抗蒸腾剂对刺槐、核桃水势日变化的影响

通过对研制出的5种抗蒸腾剂F1、F2、F3、F4、F5的3种浓度0.05%、0.1%、0.5%在刺槐、核桃幼苗上的应用效果分析,得出如下结论:5种抗蒸腾叶面肥均能抑制刺槐、核桃叶水势的下降。F1处理对两种苗木叶水势下降抑制作用最小,F5处理对两种幼苗叶水势的下降抑制作用最大。各个浓度处理中,0.5%的F5处理对两种幼苗叶水势的下降抑制作用最显著。     

Vertical and leaf-age-related variations of nonstructural carbohydrates in two alpine timberline species, southeastern Tibetan Plateau

Spatial pattern of nonstructural carbohydrates (NSC) was analyzed in two alpine timberline species (Abies georgei and Juniperus saltuaria) growing at the timberline in Sergyemla Mountain, southeastern Tibetan Plateau. We aimed to examine the effect of canopy height and leaf age on balance between carbon uptake and consumption of timberline tree species in extremely environmental condition. The results showed that no significantly vertical variation in sugars, starch or NSC (soluble sugars plus starch) in A. georgei was found for any aged needles. Also, there were no significant differences among vertical gradients in both current and last-year leaves for J. saltuaria. However, different-aged needles/leaves showed significant differences in NSC concentrations in both A. georgei and J. saltuaria. For A. georgei, needle mean NSC across vertical canopies showed a significant increase from current-year to 2-year needles (P < 0.05), followed by a gradual decrease from 2- to 5-year needles (P < 0.05), whereas for J. saltuaria, last-year leaves had significant higher NSC except sugars compared with current-year leaves across canopies (P < 0.01). The observed trends of NSC along vertical canopy heights and leaf ages suggested that, in extreme environmental condition, not only light-induced carbon acquisition in photosynthesis but also carbohydrate export from leaves should be taken into account to explain the spatial pattern of NSC.     

Senescence of Top Three Leaves in Field‐Grown Rice Plants

Abstract

The top three leaves play important roles in biomass production and grain yield of rice (Oryza sativa L.) crop since the three leaves not only assimilate majority of carbon for grain filling during ripening phase, but also provide large proportion of remobilized‐nitrogen (N) for grain development during their senescence. The objectives of this study were to (a) compare senescence of the top three leaves and (b) compare the changes in N, chlorophyll, and ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco) contents of the top three leaves after their full expansion in field‐grown rice plants. When the basis of comparison among the top three leaves was plant age in terms of days after transplanting (DAT), senescence generally started earliest in ?3rd leaf, intermediate in ?2nd leaf, and latest in flag leaf. If the basis of comparison among the top three leaves was leaf age in terms of days after full leaf expansion (DAFE), it was not clear which leaf senesced earlier. Senescence rate was generally greatest in flag leaf, intermediate in ?2nd leaf, and smallest in ?3rd leaf. Ribulose‐1,5‐bisphosphate carboxylase/oxygenase content declined earlier, and at a faster rate than N and chlorophyll contents during the senescence of all top three leaves. Correlation analysis indicated a close relationship between N and chlorophyll contents. Ribulose‐1,5‐bisphosphate carboxylase/oxygenase content correlated with N content better than with chlorophyll content. The suitability of N, chlorophyll, and Rubisco contents for quantifying the leaf senescence of field‐grown rice plants is discussed.