串果藤属(Sinofranchetia)叶的个体发育研究

对串果藤属(Sinofranchetia)叶的个体发育过程进行了观察,结果表明,其叶原基在发生时为不分裂的,其后叶原基两侧产生两个突起,形成两个侧生小叶原基,而中央部分形成中央小叶的原基。同时对串果藤属植物叶原基发生的类型等问题进行了讨论。     

源库比改变对玉米生育后期茎鞘贮存物质含量及产量的影响

通过对吐丝授粉期两种密度条件下的两个不同类型玉米品种剪1／2叶、剪1／2穗和断1／2根的研究发现：剪叶、断根减源后植株体内可溶性糖浓度下降2．19％～38．6％,剪穗缩库后可溶性糖浓度上升23．17％～38．5％,而单株生产力降低4．1％～40．94％。试验表明：玉米产量的形成与源库关系的协调性有关。     

延安地区5种灌木叶旱性结构的解剖研究

选取角质层厚度,栅栏组织厚度/海绵组织厚度,第一层栅栏组织细胞密集度,侧维管束密度,主脉厚度作为叶片旱生结构指标,对比观测了5种灌木的抗旱性能。方差分析结果显示5种灌木角质层厚度、侧维管束密度和主脉厚度均具极显著差异,多重比较显示5种灌木主脉厚度两两间差异均显著,白刺花、沙棘和文冠果叶子的角质层厚度差异不明显,黄刺玫与虎榛子之间角质层厚度差异明显;而白刺花、沙棘、文冠果与黄刺玫和虎榛子之间差异显著。用非加权指数法对树种抗旱性能大小排序结果为:白刺花>文冠果>沙棘>虎榛子>黄刺玫。     

苹果叶片组培再生系统研究进展

几十年来 ,苹果叶片培养再生技术取得了较大的进展。叶片再生主要有器官发生和胚状体发生两种途径。影响叶片再生的主要因素有基因型、培养基、叶片发育阶段及生理年龄、暗培养等。就近年来国内、外学者在此方面的研究进展、存在问题及前景作简要概述。     

Photosynthesis and Growth Responses of Parthenocissus quinquefolia (L.) Planch to Soil Water Availability

Photosynthesis and growth characteristics of Parthenocissus quinquefolia were measured under differing soil water availability within a pot. Decreased soil moisture significantly reduced the leaf relative water content (RWC) and the above- and below-ground biomass. However, more biomass was allocated to the root than to the leaf. Net photosynthetic rate (P _N), stomatal conductance (g _s), and transpiration rate (E) were also significantly decreased but water use efficiency (WUE) was increased. Midday depressions in P _N and g _s were not evident for the well-irrigated plants. With the lower water availability, midday reductions in P _N and g _s were much more marked and the duration of the depression was longer. Additionally, the P _N-irradiance response curves also indicated that water supply affected photosynthesis capacity. The growth and photosynthetic response of P. quinquefolia to water supply indicated that this species could resilient to water availabilities and adapt to Hunshandak conditions very well.     

磷缺失引起小麦叶片中脂含量的变化与脂的合成和磷脂酰甘油的降解有关(英文)

对生长在不同磷营养水平条件下小麦(Triticum aestivum var.Zhongyou 9507)叶片中光合膜脂含量变化的原因进行了研究。通过对生长在不同磷营养水平条件下9 d龄和16 d龄小麦叶片中光合膜脂含量的分析,发现在磷缺失培养条件下,小麦光合膜脂的相对含量发生了很大变化,这种变化与小麦叶龄密切相关。在16 d龄小麦植株中,第一片叶为老叶,第二片叶为较老叶,而第三片叶为新叶,PG和MGDG在叶片中的相对含量从新叶到老叶逐渐下降,而DGDG和SQDG含量逐渐上升;在磷缺失条件下,16 d龄小麦第一叶片中PG的含量(2.5％)远远低于其在9 d龄第一叶片中的含量(5.5％)。以上结果说明,磷缺失引起小麦叶片中脂含量的变化不仅与脂合成有关,而且与PG的降解有关;新生叶片中PG含量减少的主要原因是由于磷供应不足,从而影响了PG的合成;而PG的降解则是老叶中PG含量下降的主要原因。     

小麦叶片暗诱导衰老期间1,5-二磷酸核酮糖羧化酶/加氧酶的降解(英文)

研究了小麦(Triticum aestivum L.cv.Yangmai 158)叶片暗诱导衰老过程中1,5-二磷酸核酮糖羧化酶/加氧酶(Rubisco EC 4.1.1.39)的降解。发现在此期间Rubisco大亚基(LSU)发生裂解,产生50 kD的降解条带,同时在自然衰老过程中也检测到这一产物。初步实验结果表明LSU发生这步裂解时Rubisco全酶没有解离。另外,在粗酶液中当温度在30～35℃,pH7.5时,这一步裂解反应能有效进行。     

Morpho-Physiological Aspects of Productivity and Quality in Squash and Pumpkins (Cucurbita spp.)

Squash and pumpkins are important horticultural crops worldwide, but there has been relatively little research to systematically describe yield components and improve productivity in this species. This review outlines some of the basic growth-analysis techniques for describing different aspects of productivity and attempts to summarize investigations on physiological, morphological, and ecological aspects of productivity and the relationship of these factors to eating quality in the three most important domesticated species of Cucurbita—C. pepo, C. maxima, and C. moschata. The emphasis of this review is on components of yield that can be modified either by selective breeding or through use of cultural techniques. Increasing economic crop yield while also balancing the needs to maintain and improve culinary qualities of the edible product will also be discussed. The bush phenotype is being increasingly exploited in new cultivar development. Advantages and disadvantages of using bush genotypes in cultivar development are addressed. In addition, because of increasing use of Cucurbita seeds for vegetable oils, snackseeds, and pharmaceutical purposes, physiological components of seed yield are also discussed.     

防烟叶霉变菌株对烟叶霉变的影响

为有效防止烟叶霉变,采用平板对峙培养的方法,就3个防烟叶霉变菌株对霉变菌的抑制作用进行了研究．结果表明,JMBl42、B112、B329对供试霉变菌皆表现出一定的抑制作用,对不同霉变菌的平均抑制率分别为51．6％、52．9％、53．7％．3个防烟叶霉变菌株分别以每mL 10^7、10^8、10^9 cfu(colony当当forming unit)13个浓度单独处理和每mL10。cfu浓度混合处理烟叶,结果表明,JMBl42菌株每mL10,cfu处理浓度效果最好,与对照差异极显著,其次为B112菌株每mL10^8cfu处理浓度,但它与对照差异不显著,B329菌株处理效果最差,混合施用结果与对照差异不显著．由此确定JMBl42菌株每mL10^9cfu处理浓度为仓储烟叶防霉变最佳处理参数、     

Physiological and anatomical changes during the early ontogeny of the heteroblastic bromeliad, Vriesea sanguinolenta, do not concur with the morphological change from atmospheric to tank form

Two distinct morphological forms characterize the ontogeny of many epiphytic bromeliads. Smaller plants exhibit an atmospheric habit, while larger plants form water‐impounding tanks. The study of the functional significance of heteroblasty in epiphytes is severely hampered by considerable size‐related variation in morphological, anatomical and physiological parameters. To overcome this problem, plants of varying size of both atmospheric and tank form were included in the present study with Vriesea sanguinolenta. The results show that virtually all morphological, anatomical and physiological characteristics vary during ontogeny, but changes were rarely directly related to the step change in gross morphology. Changes were either: (1) gradual from smallest atmospheric to small tank (e.g. leaf divergence angles, reduction in photosystem II efficiency during drought, speed of recovery after drought); (2) there was no change between atmospheric and small tank, but a gradual or step change within the tank form (stomatal density, relationship of leaf N and specific leaf area); or (3) developmental patterns were more complicated with decreases and increases during ontogeny (photosynthetic capacity, carbon isotope ratios, abscisic acid levels during drought). Although the comparisons between ontogenetic phases were always confounded by size differences, a hypothetical small tank plant is expected to suffer higher water loss than a real atmospheric, whereas a hypothetical, large atmospheric plant would show reduced access to resources, such as nutrients, in comparison with the real tank. The present results are consistent with the notion of heteroblasty as an adaptation of early ontogenetic stages to drought, but highlight that size‐related variation greatly modifies any difference directly associated with the step change from atmospheric to tank.