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101.
102.
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. 相似文献
103.
水稻氮素供需差与不同叶位叶片氮转运和衰老的关系 总被引:22,自引:4,他引:22
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 相似文献
104.
105.
悬铃木叶片再生体系的建立 总被引:9,自引:0,他引:9
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。 相似文献
106.
Effects of N, NP, and NPKS fertilizers applied to four-year old hybrid poplar plantations 总被引:1,自引:0,他引:1
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. 相似文献
107.
108.
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. 相似文献
109.
《Journal of plant nutrition》2013,36(12):2453-2468
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. 相似文献
110.
有机肥施用方式对柑橘园土壤肥力和柑橘养分、品质的影响 总被引:2,自引:0,他引:2
为提高上海崇明柑橘的品质和产量,研究了不同有机肥施肥量和施肥深度对柑橘园土壤肥力和柑橘养分、品质的影响.结果表明:与未施有机肥处理相比,施用有机肥可以不同程度地增加土壤中速效N、有效P和有效K的含量,最好的处理分别高出对照20.9%、24.9%和44.4%;并能提高土壤有机质的含量,最好的处理高出对照16.2%;同时减小土壤容重,降低土壤的pH,从而提高土壤肥力;施用有机肥可以增加土壤中微生物的数量,并且能提高柑橘叶片中全氮和全钾的含量,改善柑橘果实品质. 相似文献