中国南瓜无蔓性状种间遗传研究

为探讨向印度南瓜及美洲南瓜中转育中国南瓜无蔓性状的意义及可行性,进行无蔓中国南瓜种间杂交试验,采用田间调查结合RAPD分子标记鉴定的方法研究中国南瓜无蔓性状种间遗传规律。通过比较中国南瓜无蔓性状在南瓜属3个种中的遗传表现发现：中国南瓜无蔓性状在种间杂种F1、F2及BC1F1中的分离比例符合孟德尔遗传规律;与种内杂交不同,无蔓中国南瓜与蔓生异种南瓜材料的种间杂交一代表现出节间变长的倾向,表现为不完全显性遗传;通过种间杂交,可将中国南瓜特有的无蔓性状转育到美洲南瓜及印度南瓜中,创造全新的种质资源。     

不同整枝方式对密本南瓜产量影响

为提高南瓜生产水平,对密本南瓜进行了整枝试验.结果表明：在遵义县试验条件下,整枝留2条子蔓和留3条子蔓能使密本南瓜提前7d采收,单瓜重比不整枝的高30％和31.69％,单产比不整枝的分别高27.56％,29.75％.说明密本南瓜整枝更有利于获得更大的经济价值.     

中国南瓜F_1砧木对黄瓜嫁接苗生长的影响

用前期试验筛选出的较耐盐的中国南瓜F1360-3×112-2、077-2×112-2、360-3×635-1为黄瓜砧木,用生产上常用的黄瓜砧木黑籽南瓜作对照,以津春2号黄瓜品种为接穗,采用靠接法和插接法在温室营养钵育苗条件下,研究中国南瓜F1作为黄瓜砧木的嫁接亲合性和对嫁接苗生长的影响。结果表明,中国南瓜F1幼苗由于下胚轴较细,嫁接成活率比黑籽南瓜低,采用插接法嫁接成活率优于靠接法。嫁接20 d后360-3×112-2和360-3×635-1作砧木的嫁接苗单株叶片数、最大叶片面积、根系和地上部鲜质量不低于黑籽南瓜嫁接苗,因此具备作为黄瓜砧木的基本条件,其中360-3×112-2嫁接苗根冠比较高,幼苗健壮,适宜作为黄瓜砧木在生产中使用。     

南瓜CmNAC基因片段的克隆与序列分析

NAC转录因子是特异存在于植物中具有多种生物功能的新型转录因子,其家族成员N端含有保守氨基酸序列,C端为高度变异的转录激活区。本项研究以南瓜叶片为材料,根据甘蓝型油菜NAC1、番茄NAC、辣椒NAC保守结构域设计一对简并引物,采用RT-PCR方法扩增得出长度约为440 bp大小的DNA片段,将其克隆至pMDl9-T载体上,而后对重组克隆进行测序,用BLAST和DNAMAN软件对核酸及氨基酸序列进行分析,结果表明所获得的南瓜NAC基因片段由442个碱基组成,编码147个氨基酸,命名为CmNAC。该基因片段具有其他植物NAC基因中存在的保守区,并且属于NAC家族中ATAF1/2亚家族。     

不同化学物质调控塑料大棚南瓜营养生长和生殖生长的研究

为实现塑料大棚南瓜营养生长与生殖生长的关系处于合理状态,研究选用不同化学物质诱导大棚南瓜雌花发生和控制营养生长。试验以‘永安二号’（印度南瓜类型）为材料,在南瓜苗期施用不同化学物质进行处理。结果表明：南瓜苗期用增瓜灵、乙烯利能够明显降低第一雌花节位、促进提早开花并增加雌花数量,以100 mg/L 乙烯利处理促进雌花发生效果最佳;多效唑、矮壮素、增瓜灵均有拟制营养生长的作用,500 mg/L多效唑和200 mg/L矮壮素控生效果最佳。增瓜灵（每袋15 g 兑水3 kg）具有促进雌花生成、抑制营养生长的双重作用。该试验在南瓜苗期用4 种化学物质进行处理,表现出明显的诱雌和控生优势,可以在农业生产中广泛应用。     

黑籽南瓜种间杂交研究

通过调整播期克服了南瓜属种间花期不遇的问题,以美洲南瓜、中国南瓜、印度南瓜3个种共12个材料与黑籽南瓜进行了种间杂交试验。黑籽南瓜为母本不结实,以其他3个种为母本则均可结实。美洲南瓜×黑籽南瓜及印度南瓜×黑籽南瓜杂交获得的果实内均无种子。获得了18株中国南瓜×黑籽南瓜F1植株。种间杂种F1植株雄蕊退化,以其作为母本以中国南瓜或黑籽南瓜为父本进行回交,可结实但无种子。中国南瓜×黑籽南瓜F1形态为双亲中间型偏父本,其抗病性、抗虫性不及父本黑籽南瓜而倾向于母本中国南瓜。     

中国南瓜可溶性固形物含量的主基因+多基因遗传分析

为明确中国南瓜可溶性固形物含量的遗传规律,选用中国南瓜杂交获得的6世代群体(P1、P2、F1、F2、BCP1、BCP2)为材料,应用植物数量性状的主基因+多基因遗传模型研究其遗传规律。结果表明,该群体可溶性固形物含量的遗传符合2对加性-显性-上位性主基因+加性-显性多基因混合遗传模型,2对主基因的加性效应均为-0.7077,均使可溶性固形物含量降低;显性效应分别为3.5034和1.3586,均使可溶性固形物含量升高。多基因的加性效应和显性效应分别为2.3066和-0.6679。其主基因遗传率在BCP1、BCP2、F2分别为17.06%、56.01%、95%,多基因遗传率在BCP1、BCP2、F2分别为47.16%、18.78%、0;说明主基因表现出较高的遗传力,可以在早期世代对可溶性固形物含量进行选择。研究为中国南瓜育种品质性状选择和分子标记辅助选择提供了理论依据。     

中国南瓜（C.Moschata）F2群体分子标记偏分离的遗传分析

本研究以中国南瓜A-3与B-5构建的F2群体为材料,对果实长棒型Is和果皮全黄yf形态标记及具有多态性的87对引物进行分析。研究结果显示:89个标记中,在p<0.01显著水平上,有5个标记发生偏分离,频率为5.6%,在p<0.05水平上,有12个标记发生偏分离,频率为13.5%;偏分离标记成簇或者单个分布在9个遗传连锁群上,成簇分布的热点区域分布主要分布在LGp2、LGp6、LGplO连锁群上,其中11个标记偏向父本B-5,2个标记偏向杂合体,3个标记偏向双亲,分别占总偏离标记的64.70%, 17.65%和17.65%。本研究分析了偏分离产生的原因,推测配子体选择可能是多态性位点产生偏分离的重要因素。     

春见桔橙耐贮性及理化性状变化研究

摘要：为了确定春见桔橙的最佳销售时期,提高经济效益;将春见桔橙[(Citrus reticulata × C. sinensis) cv. Okitsu No. 44]果实采收后常温贮藏135d,对储藏期的果实单果重、果皮厚度、果汁率,可溶性固形物、酸含量、固酸比、糖酸比,腐果率、果实病害类型等变化规律进行研究;结果表明：春见桔橙贮藏性能较好;糖含量在贮藏75d内呈上升趋势,75d后开始缓慢下降;贮藏90d后单果重较显著下降;可食率和果汁率在贮藏90d内呈上升趋势,随后逐渐呈下降趋势;贮藏期间腐果率呈幂函数变化;青绿霉病是引起果实腐烂的主要病害。结论：贮藏前期（45d）含酸量的大幅降低是导致糖酸比值和固酸比值升高、品质提升的最主要原因;贮藏45d后是较为适宜的食用时期;春见桔橙在采收时并未进入真正的成熟期,翌年1月中旬真正成熟。     

Inheritance of aroma compounds in a model population of Fragaria × ananassa Duch.

The inheritance of important aroma compounds is demonstrated by the use of a model population of Fragaria  ×  ananassa . Two cultivars were chosen for the crossing, 'Mieze Schindler' and 'Elsanta', which differ strongly in pedigree, phenotype, and fruit traits, including flavour. Two hundred seedlings of this cross-combination were randomly selected from a population of 438 seedlings and propagated, with three plants per seedling. Aroma analysis was performed by automated headspace solid phase micro-extraction in combination with non-targeted data analysis (pattern recognition). This method can assist breeding programmes by the preparation and analysis of hundreds of samples by a simple procedure. The method was backed up by the substance identification using gas chromatography/mass spectrometry. Data processing of 78 detectable volatile compounds by Chromstat^TM in the F₁ population showed very high variability of the volatile patterns. The ester methyl anthranilate (MA) is a discriminative key compound, being present only in the mother cultivar 'Mieze Schindler', and not detectable in 'Elsanta'. Methyl anthranilate was detectable in one fourth of the F₁ population. This low degree of inheritance shows that this important compound is easily lost in the breeding process, which could explain why all investigated modern cultivars do not contain MA. The results are valuable for the choice of breeding partners and for selection in seedling populations.     

Inheritance of resistance to Zucchini yellow mosaic virus in the interspecific cross Cucurbita maxima × C. ecuadorensis

Summary More than 200 accessions of three wildLactuca species were screened in the laboratory for race-specific resistance toBremia lactucae. Only a fewLactuca entries showed resistance both as seedlings and in a leaf disc test. Accessions ofL. serriola andL. sativa had a low degree of resistance. The best entries were also compared under field conditions. TheL. saligna entries were totally free from disease in the field test. High resistance was also recorded in a fewL. serriola entries and in lettuce cultivars such as Saffier and Mariska.     

Effects of Wheat Chromosome 1D Telosomes on Hybrid Seed Development in Wheat × Rye Crosses

Pollination of ‘Chinese Spring,’ monosome 1D plants with rye results in failure of hybrid seed development in a proportion of the F₁ seeds corresponding to the transmission rate of the nullisomic 1D egg cells. Development and viability of these hybrid seeds closely resemble that normally observed in T. aurum× rye crosses. Using ‘Chinese Spring’ chromosome ID telosomic plants in crosses with rye, it was possible to illustrate that the observed effect was associated with the long arm of this chromosome.     

Impact of puroindoline b alleles on the genetic variation for hardness in soft × hard wheat crosses

Wheat grain hardness is controlled by one major genetic factor, the puroindoline hardness (ha) locus on the short arm of chromosome 5D, but there is also evidence for other minor genetic factors modifying the effect of puroindoline alleles. In this study, the progeny of nine soft × hard wheat crosses was evaluated for kernel texture, and the allelic state of puroindoline b (pinB) was assessed by polymerase chain reaction. The F₂ populations of all nine crosses showed the expected 1:2:1 segregation ratio of homozygous soft, heterozygous medium and homozygous hard offspring. A model of variance components was constructed to separate the effects of pinB‐D1 allelic variation from other genetic factors affecting endosperm hardness. This model showed that pinB‐D1 allelic variation could explain 75‐93% of the genetic variation for hardness in the F₂, but there were also significant contributions from other genetic factors in all the crosses. The feasibility of pinB‐D1 alleles as a molecular marker for hardness is demonstrated, and the results also indicate the possibility of breeding wheat varieties with true medium hardness.     

普通小麦与粗山羊草正反交育性机理的胚胎学研究

用石蜡切片和塑料切片法,对中国春与粗山羊草正、反交授粉后不同时间固定的子房进行了胚胎学研究.结果表明,虽然正、反交均能受精发育,但两者的受精率和成胚率相差极大.正交组合的平均受精率和成胚率分别为23.75%和4.58%;而反交组合的平均受精率和成胚率分别为87.08%和82.08%.尽管如此,正交所形成的正常胚的质量比反交形成的     

平欧杂种榛的继代培养条件优化研究

由于传统榛子繁育方法不能满足市场的需求,以平欧杂种榛‘辽榛7号’为材料,采用离体培养的方式对其继代培养中基本培养基及其激素配比进行研究,以期找到一条切实可行的榛子扩繁技术.结果表明:(1)与DKW培养基、NRM培养基和WPM基本培养基相比,选用改良NRM培养基作为平欧杂种榛组培苗继代培养的基本培养基;(2)选择2.5 mg/L6-BA和0.01 mg/LIBA作为继代培养的激素组合,隔代降低其浓度至6-BA 2.0 mg/L和IBA 0.005 mg/L有利于促进组培苗的增殖;(3)根据组培苗生长状况,添加TDZ的适宜浓度范围为0.001～0.01 mg/L,其中以0.005 mg/L的增殖效果最好;(4)培养基中添加多胺对组培苗茎段增殖具有良好的效果,但GA3的作用不明显,同时添加GA3和多胺,其增殖效果较单独添加GA3好,但较单独添加多胺差.     

Maternal inheritance of male sterility in the progeny of a natural hybrid between Cajanus lineatus and C. cajan

Adoption of pigeonpea hybrids in central and southern India is showing high impact with on‐farm yield advantages of >30%. The hybrid pigeonpea technology, the first in any legume crop, is based on a cytoplasmic‐nuclear male‐sterility (CMS) system. For a long‐term sustainability of hybrid programme, it is imperative that both nuclear diversity and cytoplasmic diversity are maintained among hybrid parents. In this context, a continuous search for new CMS‐inducing cytoplasms is necessary. This paper reports detection of maternal inheritance of male sterility in the progeny derived from a natural hybrid between a wild relative [Cajanus lineatus (W. & A.) Maesen comb. nov.] of pigeonpea and an unknown pigeonpea [Cajanus cajan (L.) Millsp.] genotype. In the present study, the male sterility was maintained up to BC₇F₁ generation by an advanced breeding pigeonpea line ICPL 99044. This male sterility inducing cytoplasm of C. lineatus was tagged as A₆. In future, this CMS genetic stock can be used to develop a range of new pigeonpea hybrids with high yield and adaptation.     

陆地棉和海岛棉的黄萎病抗性遗传研究

以3个海岛棉品种和5个陆地棉品种配制的23个正反交组合的四个分离群体(F1、F2、BC1和BC2)为材料,以中等致病力的安阳菌系接种,研究陆地棉和海岛棉黄萎病抗性的遗传规律。结果表明,海岛棉品种间杂交,F2和BC2抗病和感病单株的分离比例均符合3∶1和1∶1,其黄萎病抗性是由一个显性基因控制;陆地棉品种间F2和BC2的抗病和感病单株的分离比例也均符合3∶1和1∶1,其黄萎病抗性也是由一个显性基因控制。用海岛棉抗病品种与陆地棉抗病品种进行种间杂交,其F2和BC2的抗病株均在95%以上,而用海岛棉抗病品种与陆地棉感病品种进行杂交,其F2和BC2抗病株和感病株的分离比例符合3∶1和1∶1,表明海岛棉和陆地棉的黄萎病抗病基因可能位于同一基因位点。     

长采收期桃果实硬度变化与相关激素含量关系的研究

为探讨长采收期桃-双久红果实成熟前后硬度变化与相关内源激素的关系,以普通桃品种—川中岛为对照,在果实成熟前后各20d对其果肉硬度和内源IAA、ABA、CTK、GA3的含量和乙烯释放量进行了测定。结果表明:随着果实的成熟,川中岛果实的硬度迅速下降,双久红果实的硬度则一直保持较高的水平;川中岛果实的乙烯释放量在成熟后5d出现高峰,而双久红则一直处在较低的水平;川中岛桃果肉中IAA、ABA含量、ABA/IAA值均明显高于双久红的,ABA含量与果实硬度呈显著负相关;随成熟度的加大,两类型桃果肉中CTK、GA3含量都呈下降趋势,但双久红桃果肉中的CTK、GA3含量明显高于川中岛的。     

Effects of Temperature on Pollen Tube Growth and Fruit Set in Reciprocal Crosses Between Cucumis sativus and C. metuliferus

Interspecific hybridization between Cucumis sativus and C. metuliferus may be used to introduce disease resistance into the cultivated cucumber. Hybrid plant development, however, is restricted by strong barriers to crossing. The present study was undertaken to examine temperature effects on pollen tube growth and fruit set in reciprocal crosses between C. sativus and C. metuliferus. When crossing C. sativus×C. metuliferus, at 20°C, pollen tube growth was arrested in the stylar region of the pistil and no fruits containing embryos were found. However, at 23° and 26°C, C. metuliferus pollen tubes penetrated into the C. sativus ovules. The enhanced pollen tube penetration was correlated with improved embryo development. Although pre-fertilization barriers were overcome, post-fertilization barriers caused abortion of hybrid embryo development at the globular stage. No effects of higher temperatures were found in the cross C. metuliferus×C. sativus; Pollen tubes were generally arrested in the stylar region of the pistil.     

phlb 基因对普通小麦×易变山羊草Ae.variabilis杂种F1、BC1、BC2、BC3及转移抗禾谷类根结线虫 M.naasi基因影响的研究

Courtot 4 phlb、Courtot 2 phlb、Courotot与 Ae.variabilis杂种F_1平均每PMC在MI染色体交叉数(Xta)分别为15.18、11.62、1.67。杂种F_1育性极差,自交不结实。Courtot 4phlb、Courtot 2 phlb与Ae.variabilis杂种F_1回交难,回交结实率仅分别为0.13％、1.66％;BC_1植株染色体少,93.1％的植株为2n=35-44,且减数分裂行为极不规则。在2phlb×Ae.variabilis×2phlb×Ph×Ph BC_3群体中可获遗传性较稳定、育性较正常、对 M.naasi抗性一致的重组系或易位系。而Courtot×Ae.variabilis杂种F_1回交较易成功（6.81％）。93.8％的BC_1植株染色体数变化在2n=47-56,BC_3中仅获抗M.naasi单体附加系。