不同瓤色西瓜果实中Vc含量差异

西瓜富含维生素C,但不同瓤色西瓜果实中Vc含量的差异没有报道。以37个二倍体西瓜品种、19个三倍体西瓜品种及25个四倍体西瓜品种为材料,采用碘量法测定了西瓜成熟果实中Vc含量。结果表明:不同瓤色材料的Vc含量差异显著,二倍体、三倍体、四倍体黄瓤品种Vc平均含量分别是红瓤品种的1.88倍、1.86倍、1.32倍。选种或食用时选用黄瓤品种能获得较多的Vc。     

混合盐胁迫对二倍体刺槐和绒毛白蜡根系形态和抗氧化指标的影响

以二倍体刺槐和绒毛白蜡幼苗为材料,配制NaCl和Na2CO3混合盐梯度,比较2种植物根系生物量和形态差异,测定根系保护酶活性以及膜脂过氧化产物和可溶性蛋白含量,以探讨盐碱胁迫对植物根系生长和生理的影响。结果表明:1)低盐碱胁迫(80mmol·L^-1盐浓度)促进二倍体刺槐根系生物量、总长度、总表面积和总体积增加,而抑制绒毛白蜡根系生物量和形态指标;2)绒毛白蜡根系SOD活性对低混合盐浓度敏感,而二倍体刺槐根系SOD活性在高盐浓度下显著上升;2种植物根系POD活性在低盐浓度下最大,CAT活性在240~320mmol·L^-1盐浓度下达到峰值;3)二倍体刺槐根系中MDA含量高峰值出现在低盐浓度下,绒毛白蜡则出现在240mmol·L^-1浓度;随着混合盐浓度增加,二倍体刺槐根系可溶性蛋白含量逐渐降低,绒毛白蜡则先升高后降低;4)多因素方差分析表明,2种植物根系主要形态指标间存在物种间差异,混合盐胁迫对根系形态和抗氧化生理指标的影响不同。在盐碱胁迫下,二倍体刺槐和绒毛白蜡根系表现出适应性差异。     

Primary studies on tissue culture from mature embryos in diploid and tetraploid wheat

Using mature embryos (MEs) as the explants, the callus induction, embryogenic callus differentiation, plantlet regeneration and culture efficiency in diploid and tetraploid wheat of four genotypes were studied. The tested four genotypes wheat included cultivable emmer wheat (Triticum dicoccum Schuble), durum wheat (Triticum durum Desf.) and the common wheat progenitors Triticum dicoccoides and Triticum aegilopides. Results indicated that there were significant differences in the efficiency of callus induction, callus differentiation and plant regeneration among the tested genotypes. The efficiency of differentiation and regeneration shows strong genotype dependence. The rates of callus induction, embryogenic callus differentiation, plantlet regeneration and culture efficiency respectively were 95.00%, 90.00%, 32.40%, and 27.70% in cultivable emmer wheat, which were significantly higher than other tested genotypes. Therefore, this study has provided a basis for genetic transformation, gene cloning and molecular plant breeding in wheat and other related species. __________ Translated from Molecular Plant Breeding, 2007, 5(4): 480–484 [译自: 分子植物育种]     

Soft-rot resistance combined with other tuber characters in long day-adaptedSolanum phureja

Summary Offspring were produced from a cross between two long-day-adaptedSolanum phureja clones which carried resistance to tuber soft rot (Erwinia carotovora subsp.atroseptica). In tests carried out on the produce of field-grown plants raised from tubers, over fifty per cent of the 173 offspring were found to be highly resistant. Assessments were also carried out of tuber yield, mean tuber weight, tuber number, shape, regularity, flesh colour, texture of the steamed flesh, fry colour, after-cooking blackening, sprout length after storage and overall dormancy. There were statistically significant differences between clones for all characters (P<0.001). Twelve of the clones were selected on the basis of high resistance, yield, tuber weight, regularity of shape and absence of after-cooking blackening. The value of resistant long-day-adapted diploid material for commercial breeding is discussed.     

Harvest management based on leaf stage of a tetraploid vs. a diploid cultivar of annual ryegrass

Leaf stage‐dependent defoliation is linked to the plant's physiological status and may be a more suitable criterion than time‐based intervals for harvesting forage grasses, but no reports of research with annual ryegrass (Lolium multiflorum Lam. var. westerwoldicum) were found. To address this, a 2‐year field study was carried out at Raymond, MS, on a Loring silt loam soil (fine‐silty, mixed, thermic Typic Fragiudalfs). Forage production, morphological characteristics and nutritive value responses to defoliation based on leaf stage (2, 3 and 4 leaves per tiller) and two residual stubble heights (RSH; 5 and 10 cm) of a tetraploid (“Maximus”) vs. a diploid (“Marshall”) cultivar of annual ryegrass were quantified. Forage harvested, in 2011, increased linearly as leaf stage increased from 7.3 to 8.8 Mg/ha, but during 2012 was least (7.0 Mg/ha) at 3‐leaf stage and similar at the other two leaf stages (7.6 Mg/ha). Tiller density was less for Maximus (1,191 tillers/m²) than for Marshall (1,383 tillers/m²). Leaf blade proportion decreased with increasing leaf stage and was greater by 9% for Maximus than for Marshall. Generally, forage nutritive value became less desirable with increasing leaf stage. There was a dichotomy in forage harvested and nutritive value responses, but maximum forage productivity was achieved when annual ryegrass was defoliated at the 4‐leaf stage interval.     

二倍体与三倍体虹鳟(Oncorhynchus mykiss)红细胞及部分血液指标的比较

对三倍体和二倍体虹鳟(Oncorhynchus mykiss)的红细胞大小(长、短径值和体积)、形态及部分血液指标(红细胞数、血红蛋白、红细胞压积、红细胞脆性和白细胞数)进行了比较。结果表明:三倍体虹鳟红细胞体积与二倍体比值为1.51∶1,细胞核大小与二倍体比值为1.49∶1,与理论值(1.5∶1)比较均无显著差异(P>0.05)。二倍体红细胞短径/长径比值为0.63,呈现出椭圆形;三倍体红细胞短径/长径比值为0.60,呈现出明显的长椭圆形,并有19%的红细胞有哑铃形或分裂的细胞核,这可作为区别二倍体鱼类的一个重要鉴定标志。三倍体虹鳟的红细胞数、红细胞压积和红细胞脆性明显小于二倍体(P<0.05),而血红蛋白与白细胞数与二倍体比较无明显差异(P>0.05)。     

金叶榆二倍体及其同源四倍体的生理特征与转录组差异分析

本文旨在探究金叶榆（Ulmus pumila cv.‘Jinye’）二倍体及其同源四倍体的生理特征和差异基因表达情况,为金叶榆关键调控基因的定位及基因工程育种提供分子基础。试验以金叶榆二倍体及其同源四倍体为材料,比较两者叶绿素相对含量,可溶性糖、可溶性蛋白、MDA含量,SOD和POD活性等生理指标,并进行转录组测序。结果表明：金叶榆同源四倍体叶片中叶绿素相对含量,可溶性糖和可溶性蛋白含量及SOD、POD活性显著高于二倍体,MDA含量显著低于二倍体。转录组测序共得到1 283个差异表达基因,其中1 078个表达上调,205个表达下调。995个差异表达基因被GO功能注释,与代谢过程、细胞过程、催化活性、结合和转运蛋白活性等密切相关;COG注释结果显示,主要注释在碳水化合物的运输和代谢、次生代谢产物合成和脂质运输和代谢;KEGG通路分析发现,植物激素信号转导通路差异显著性最为明显,其中生长素、油菜素内酯和水杨酸信号转导途径富集基因数最多。参与代谢过程、催化活性和激素信号转导通路等关键基因的差异表达,可能与同源四倍体植株能源物质含量高、酶活提高及生长势和抗逆性增强有关。     

马铃薯4x-4x和4x-2x杂种后代高世代选系总产和商品薯产量比较

传统的4x-4x杂交方法很难进一步提高马铃薯（Solanum tuberosum L.）产量，倍性操作育种技术为提高马铃薯产量提供了新途径。试验比较4x-4x和4x-2x杂种后代高世代选系总产、商品薯产量的差异，探讨利用倍性操作育种的可能性。从4x-4x和4x-2x组合根据块茎性状和产量各选出17个高世代无性系，按随机区组设计，3次重复，在黑龙江省加格达奇比较两种组合类型高世代选系总产和商品薯产量的差异。4x-4x和4x-2x组合后代高世代选系在总产量方面无差异，但从4x-2x组合中可以选出更多的高产无性系。4x-2x组合高世代选系商品薯产量显著低于4x-4x组合，这主要是由于4x-2x组合后代选系单株结薯多，但单薯重低。采用4x-2x组合方式育种可有效利用具有丰富遗传变异的二倍体种质资源，但要注意在二倍体水平上选择，重点改良二倍体种或二倍体杂种对长日照的适应性，以及块茎性状，提高大薯率。     

小白菜杂交组合配制及自交系选育试验研究

把小孢子培养获得的22个小白菜加倍二倍体（DH）纯合植株分为 A、B两组进行组间杂交以及自交，对获得的41份杂交组合的叶片形状和叶柄色等外观品质性状进行观测分析，并对相应数据进行聚类分析，结合植株的田间表现，筛选出优良的杂交组合和亲本。结果表明：1）两个相同亲本的正反交组合外观商品性状可能存在差异；2）6个抗性强、耐衰老的杂交组合，其单株产量均高于0.4 kg，属于商品性状优良的杂交组合，其中A7 B2可作为特色分蘖组合；3）筛选出 A2、A5、A7、B6、B8、B9、B10、B118份骨干亲本自交系，以及 A1、A3、A9、B2和B75个特殊配合力高的亲本。     

Modes of inheritance of two apomixis components,diplospory and parthenogenesis,in Chinese chive (Allium ramosum) revealed by analysis of the segregating population generated by back-crossing between amphimictic and apomictic diploids

To investigate the mode of inheritance of apomixis in Chinese chive, the degrees of diplospory and parthenogenesis were evaluated in F₁ and BC₁ progenies derived from crosses between amphimictic and apomictic diploids (2n = 16, 2x). The F₁ population was generated by crossing three amphimictic diploids 94Mo13, 94Mo49 and 94Mo50 with an apomictic diploid KaD2 and comprised 110 diploids and 773 triploids. All the diploid F₁ plants examined were completely or highly eusporous and completely syngamic. All the triploid F₁ plants examined were highly diplosporous and highly parthenogenetic. KaD2 could not transmit its high level of apomixis via monoploid pollen grains. The BC₁ population, generated by crossing 94Mo49 with apomictic triploids found in the F₁ offspring, exhibited heteroploidy; it comprised haploid, diploid, triploid, tetraploid and various aneuploid individuals. In this generation, clear segregation was observed between diplospory and parthenogenesis. Analysis of the BC₁ population suggests that diplospory and parthenogenesis are each controlled by single dominant genes, D and P, respectively. However, all the BC₁ plants characterized as parthenogenetic were diplosporous. The absence of phenotypically eusporous parthenogenetic plants can be explained by assuming that the presence of diplospory gene is a prerequisite for the parthenogenesis gene expression in Chinese chive.