酸枣种质资源果实主要数量性状变异及相关性研究

通过对149份酸枣种质的主要数量性状进行分析研究,得出了酸枣果实主要数量性状的变异情况、主要数量性状间的相关性。以149份酸枣种质为材料,对其主要数量性状的变异和相关性进行了分析。结果表明,变异系数的分布范围很广,在6.94%~56.18%之间。可溶性总糖和单果重呈极显著正相关,和可食率呈显著正相关;可滴定酸和单果重、果核指数呈极显著负相关,和可食率、千仁重呈显著负相关,和维生素C呈极显著正相关;维生素C和单果重呈显著负相关。     

红河流域杧果种质资源主要数量性状变异与概率分级

为更好地开展杧果种质资源筛选工作,对杧果种质资源进行评价。以86份红河流域杧果种质资源为研究材料,对9个主要数量性状进行统计分析及概率分级。结果表明,9个性状变异系数范围是4.7%~28.81%,变异系数最大的是单果重,最小的是果实宽度。K-S检验显示,叶长、叶宽、叶柄长、可溶性固形物等4个性状均符合正态分布;单果重、果长、果宽、果厚、可食率等5个性状呈偏态分布,去除拖尾部分,也近似看作正态分布。9个数量性状均采用(X-1.2818S)、(X-0.5246S)、(X+0.5246S)、(X+1.2818S)4个点分为5级,使性状1~5级出现的概率分别为10%、20%、40%、20%和10%。相关性分析表明,果实单果重与果长、果宽、果厚、可食率呈显著正相关。本研究的开展可为杧果种质资源的评价及优异种质资源的筛选提供参考。     

引进枣种质资源果实主要性状变异及相关性分析

通过对引进的169份红枣资源的果实主要性状进行分析,结果表明:引进枣种质资源果实主要性状的变异幅度较大,在2.91％～36.83％之间,不同红枣品种间的形态与品质性状变异丰富,为优良品种的选育提供了理论基础;由相关性分析得出,果实的纵径和横径及果形指数三者呈极显著正相关,果实亮度和单果重呈极显著负相关,和果形指数呈显著...     

花生种质资源主要数量性状的遗传多样性和相关性分析

为了有效地利用花生种质资源,给新品种选育提供有力的数据支持,以46份花生种质资源为试验材料,对主茎高、主茎节数、第一侧枝长、第一分枝数、总分枝数、有效枝长等主要数量性状进行了遗传多样性分析和相关性分析。结果表明：花生种质在植物学性状上拥有丰富的遗传多样性,变异系数在11.19%~82.41%之间,多样性指数在0.3095~2.0468之间,平均数为1.6805,但两者的变化趋势相反。从相关分析结果来看,主茎高和主茎节数、侧枝长、单株生产力,第二次分枝数与总分枝数,单株结果数与单株生产力,叶片长与叶片宽,荚果长与荚果宽、种子长、百果重,荚果宽与种子长、种子宽、百果重,种子长与种子宽、百果重,种子宽与百果重,百果重与单株生产力,它们之间呈显著或极显著正相关,测得相关性极显著的一对表型性状中的一个就可以描述另一个性状。     

茄子种质资源主要性状评价及其相关性分析

为筛选出高产、耐高低温、适合华南地区种植的紫红长茄,从国内收集茄子种质资源15份,对株高、熟性、果色、单果重、单株产量和果形等主要性状进行描述和相关性分析,并进行单性结实性鉴定。茄子资源主要性状的相关性分析结果显示,单株产量与果实纵径、单果重呈极显著正相关,相关系数(r)分别为0.910和0.880;株高与果形指数呈极显著正相关(r=0.740);熟性与花冠色呈显著正相关,即当花冠色较深时,熟性就较晚。综合来看,比对照显著高产的是‘庆丰二号’,但‘庆丰二号’主茎有刺,果萼也有少量刺,这给果实采摘带来不便;且‘庆丰二号’不具有单性结实能力。‘春秀’和‘公牛长茄’的单株产量与对照相当,但‘春秀’和‘公牛长茄’都具有单性结实能力,即使遭遇高低温障碍也能正常结果,而对照不具有单性结实能力。因此,‘春秀’和‘公牛长茄’优于对照,在华南地区具有一定的推广前景。     

甘薯种质资源主要性状的鉴定

甘薯种质资源是甘薯育种的宝贵财富。为了充实甘薯的基因源,近几年来从国内外征集了甘薯品种、品系、种籽和近缘野生植物。1977年至1982年共征集到农家种382份,杂交种44份,国外种50份以及甘薯近缘野生植物19份。连同原来保存的材料合计农家种469份,杂交种88份,国外种81份。加上美国集团选择后代群体的选系200余份,总计近800余份。1980—1982年对这些资源材料,以     

草莓果实主要数量性状变异及相关性研究

以露地栽培的82份草莓品种(系)为材料,对其主要数量性状的变异、分布规律及相关性进行了研究和分析。结果表明,草莓果实硬度、可溶性固形物、平均单果重、最大单果重和单株产量基本呈正态分布,不同性状的变异不同;果实硬度与平均单果重、单株产量分别呈显著正相关和极显著正相关,平均单果重与最大单果重及单株产量均呈极显著正相关,最大单果重与单株产量呈极显著正相关。此研究为草莓育种的亲本选配和杂交后代预先选择提供了依据。     

肉苁蓉种质主要性状的变异和相关分析

【研究目的】研究栽培和野生肉苁蓉种质的药材形态、产量、品质及田间农艺性状的变异水平,以及各性状间的相关关系。【方法】应用Microsoft Excel和SPSS 11.5软件对61份肉苁蓉种质通过测量、称重或药典指定的HPLC法测定的16项性状指标进行统计分析。【结果】不同肉苁蓉种质间各性状差异极其显著,特别是产量与品质性状的个体差异,其中毛蕊花糖苷含量的变异系数高达91.6%。茎节以下的粗细、长度与肉苁蓉的鲜重和折干率呈极显著相关,但品质性状与形态和产量性状间均不存在正相关性,仅松果菊苷的含量与节上粗呈显著负相关。【结论】肉苁蓉不同种质间的形态与品质性状变异丰富,为优良品种的选育提供了理论和物质基础。相关性分析结果为肉苁蓉药材的育种目标、种植措施及合理采收提供了科学依据。     

北京地区海棠品种调查与数量学分类

海棠是重要的温带观赏花木,其品种分类工作还很不完善。基于野外调查,对北京地区海棠品种进行系统的调查和分类,共记载21个北美引进品种、3个国内栽培种以及1个国内野生种。选取了20个性状,以数量分类学的方法利用DPS软件进行了聚类分析,并制定了北京地区观赏海棠品种资源分类检索表。根据《国际栽培植物命名法规》(ICNCP)将25个海棠品种分为红色重瓣品种群、粉色重瓣品种群、深色单瓣品种群、浅色单瓣品种群4个品种群。海棠品种间欧氏距离为2.78~9.67,所有25个品种都能区别开,与形态分类结果基本一致。该框架既体现了二元分类法的内涵,又符合国际法规的形式。     

浙江省黑大豆种质资源主要性状分析

“第三次全国农作物种质资源普查与收集行动”浙江项目组从全省26个县(市,区)收集到黑大豆地方种质资源累计34份。本研究对这34份黑大豆种质进行连续两年的田间种植鉴定,发现这些黑大豆材料在农艺性状、遗传变异及品质性状均存在丰富的变异。基于农艺性状的分析表明,这批黑大豆材料以紫花棕毛为主,而其生育日数、百粒重、株高等性状具有显著性差异;基于品质性状的分析表明,蛋白质和脂肪含量的平均值分别为34.9%和19.4%;基于基因型的聚类分析表明,类群划分与其地理分布、农艺性状都有相关性。本研究进一步丰富了浙江省黑大豆种质资源遗传基础,为黑大豆地方种质资源的保护与利用提供了理论依据。     

影响白三叶草高频率植株再生因素的研究

以白三叶草子叶和下胚轴为外植体,进行直接再生系统中不同基本培养基成分和激素浓度的研究发现：白三叶草下胚轴顶端细胞的分化能力最强,分化率在65％以上,子叶次之,下胚轴其他部位几乎不分化。高维生素和微量元素可有效提高子叶的再生频率15％,而对下胚轴顶端细胞的分化影响不大。在6-BA 3mg／L NAA0．08ms／L的浓度下,下胚轴上段的再生频率最高,达80％以上。     

Evidence of functional unreduced gametes in Trifolium repens L.

The current research reports the first evidence of functional 2n gametes in megaspores of Trifolium repens L. Reciprocal backcrossing of a colchicine doubled hexaploid (2n = 6x = 48) T. repens × T. nigrescens (6x H-6909-5) F₁ hybrid to T. repens produced four seeds from 1700 pollinations. The backcross involving 6x H-6909-5 as the female parent and T. repens as the male resulted in only one seed which was, as expected, a pentaploid (2n = 5x = 40) presumably carrying four genomes of T. repens and one genome of T. nigrescens. On the other hand, those backcrosses which utilised T. repens as the female parent and 6x H-6909-5 as the male parent, resulted in 3 viable seeds. These were unexpectedly all heptaploid (2n = 7x = 56) with presumably six genomes of T. repens and one genome of T. nigrescens. The occurrence of heptaploids from a T. repens × 6x H-6909-5 (4x–6x) cross can only be explained by the union of n (= 3x = 24) pollen from 6x H-6909-5 with 2n (= 4x = 32) eggs from T. repens. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effects of divergent selection on correlations between morphological traits in white clover (Trifolium repens L.)

The effects of two generations of divergent selection for stolon diameter and stolon amount on the pattern of phenotypic correlations between important agronomic traits in white clover (Trifolium repens L.) were studied. The effects of selection were: the proportions of the variances of traits under direct selection were considerably lower within selection lines than overall and this was associated with a loss of correlation between traits. Unselected traits showed higher proportions of variances remaining within the selection lines and shifts from non-significant to significant correlations from the plants overall to selection lines. The significance of these results and their relevance to strategies of germplasm improvement is discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Nitrogen Fixation by Hybrids of White Clover (Trifolium repens L.) and Trifolium nigrescens

Development of hybrids between white clover ( Trifolium repens L.) and Trifolium nigrescens provides a novel route for genetically improving the reproductive capacity of white clover, provided the hybrids are agronomically viable, particularly with respect to N₂ fixation. A comparative study of growth and rates of N₂ fixation over 21 days was conducted with the parental species, F ₁ hybrids and backcross hybrids, in flowing solution culture, without a supply of mineral N to the plants. T. nigrescens was unable to fix N₂ in association with the strains of Rhizobium leguminosarum biovar. trifolii selected for inoculation. Rates of N₂ fixation per plant increased in the order T. nigrescens < F ₁ hybrid < T. repens < backcross 1. Specific rates of N₂ fixation (days 0–21) increased in the order T. nigrescens < F ₁ hybrid < backcross 1 <  T. repens . Dry matter production and nodule biomass per plant increased at a higher rate in backcross 1 hybrids than in T. repens. The results suggest that the potential for N₂ fixation by backcross 1 hybrids is at least as great as that by T. repens .     

Morphological characteristics of hybrids between white clover, Trifolium repens L., and Caucasian clover, Trifolium ambiguum M. Bieb

Hybrids between the stoloniferous Trifolium repens (2n = 4x = 32) and the rhizomatous Trifolium ambiguum (2n = 4x = 32) have been produced using T. repens as the recurrent parent. Morphological characteristics of the parent species and the F₁, BC1, BC2 and BC3 hybrids were examined in a glasshouse experiment. Leaflet ratios and general plant shape indicated that the BC3 hybrid was similar to T. repens. Separation of plants into components of above- and below-ground growth showed that T. repens had a greater total plant dry weight than T. ambiguum but 24% of its dry weight was in roots compared with 22% in roots and 44% in rhizomes in T. ambiguum. The BC3 generation contained plants that were predominantly T. repens-like with stolons, but also had a small proportion of their total dry weight (3%) as rhizome, confirming the potential to produce plants that combine stoloniferous and rhizomatous growth. The proportions of rhizome and stolon varied within the BC3 generation, enabling farther selection and plant breeding. The BC3 hybrids produced similar numbers of inflorescences to T. repens however, fertility was lower, although there was some variation within the BC3 for both characters.     

低温处理对白三叶叶绿素、可溶性糖和丙二醛等的影响

为探索低温胁迫对白三叶的叶绿素、可溶性糖和丙二醛等生理指标的影响,为白三叶的抗寒性育种和资源的合理利用提供基础数据,试验以新品系08-2和海法白三叶(Trifolium repens L.‘haifa’)为材料,依次设置10℃、5℃、0℃、-5℃、-10℃、-15℃等6个处理,研究低温下叶绿素、可溶性糖和丙二醛等的变化,对材料的抗寒性进行评价。结果表明,变温对白三叶的叶绿素、可溶性糖和丙二醛等的影响较大。随着温度的降低,白三叶的叶绿素含量总体呈现降低的趋势,在较低(≤0℃)温度处理下,08-2的叶绿素含量降低速度小于海法的;08-2的可溶性糖含量在0℃时达到最高,海法的在5℃达到最高;丙二醛含量和电导率逐渐升高,但08-2变化幅度低于海法。综合分析表明,新品系08-2耐寒性优于海法白三叶。     

Self-compatibility and heterosis in white clover (Trifolium repens L.)

Inbred lines of white clover (Trifolium repens L.) have been produced utilising the rare self-fertility (Sf) allele. Twenty-two lines of four distinct groups have been maintained through five generations of selfing by single seed descent. Fourteen lines were used in crosses to produce F¹s. Both parents and hybrids were analysed for a range of morphological characters. Positive heterosis for dry matter production was observed in half the hybrids. No other trait showed significant heterosis. The degree of heterosis appears to be related to the extent of variation in morphological characters between the parental lines, some combinations of lines yielding heterotic hybrids in all cases, others in none. The majority of the F¹ hybrids are superior in terms of dry matter production to eight control varieties. This revised version was published online in July 2006 with corrections to the Cover Date.     

铜尾矿对白车轴草种子萌发和幼苗生长的影响

四川彭州铜尾矿库尾沙中含有铜、镍、铅、锌、镉等重金属元素，除镍和锌元素外，其它几种重金属元素含量均已超过国家标准，对土壤和水源造成污染。该尾矿沙能够延迟白车轴草（Trifolium repens L.）种子的萌发，使胚根长度和小苗重量降低，但对最终发芽率无影响。盆栽改良试验表明，铜尾矿沙能够降低白车轴草的根系活力、叶绿素含量和生物量，增加无污染土壤的比例可以使其伤害降低。     

Nitrogen Fixation in Hybrids of White Clover (Trifolium repens L.) and Caucasian Clover (Trifolium ambiguum M. Bieb)

Hybrids between white clover (Trifolium repens L.) and Caucasian clover (or Kura clover, Trifolium ambiguum M. Bieb) are a potential route for the improvement of drought tolerance and persistence in white clover. However, to be agronomically viable they must show no significant reduction in their potential for nitrogen fixation relative to white clover. A comparative study of growth rate and nitrogen fixation was carried out in flowing solution culture without a supply of mineral nitrogen to the plants. The two parental species and two generations of backcross hybrids, with white clover as the recurrent parent, were assessed. The growth rate and N content of T. ambiguum were significantly lower than those of the other lines. However, dry matter production, nodule biomass per plant and rates of fixation were similar in second‐generation backcross plants and white clover. The results suggest that the agronomic potential of this novel germplasm is not compromised by limitations with respect to nitrogen fixation.     

白三叶草坪春季昆虫群落构成的研究

对白三叶(Trifolum repens.L.)草坪春季昆虫群落系统进行了调查及分析,结果表明：白三叶草坪春季昆虫群落由9目28种组成。其中蚜虫、叶螨是春季昆虫群落的优势种。在白三叶草坪昆虫群落演替中,通过对N, S, T, H四个指数的分析,表明4月份昆虫群落比较旺盛,但5月份昆虫群落结构更稳定协调。这些研究为白三叶草坪害虫综合治理提供依据。