芝麻远缘杂种胚胎的营救和植株再生

以栽培种中芝５号、中芝８号、宜阳白和犀牛角为母本，以野生种为父本对其杂种胚的败育时间、营救技术及植株再生进行了研究。结果显示：授粉后９—１３天为杂种胚营救的较佳时期。ＭＳ矿质＋Ｎｉｔｃｈｅｒ有机营养＋ＢＡ０．２ｍｇ＋ＧＡ３０．１ｍｇ＋ＣＨ６００ｍｇ＋ＰＶＰ０．２％＋蔗糖５％能促进杂种胚的体外发育。幼胚在ＭＳ中萌发后采用ＭＳ＋ＰＰ３３３０．１ｍｇ＋ＢＡ０．２ｍｇ的培养基可壮苗促芽，在ＭＳ＋ＮＡＡ０．５ｍｇ培养基中可形成正常试管苗．再生植株在２５℃—３２℃温室中能正常开花结实．种子具生活力．     

花生栽培种与双二倍体野生种杂种（F_2）杂交试验

以花生四大类型栽培种为母本，４个人工合成双二倍体野生种杂种为父本组成１６个杂交组合，结果表明：１６个组合的花果率和针果率变化范围都很大，显示各组合间杂交亲和力有较大的差异。野生种杂交种中以（Ａｒａｃｈｉｓ．ｃａｒｄｅｎａｓｉｉ×Ａｒａｃｈｉｓ．ｂａｔｉｚｏｃｏｉ）Ｆ２为父本与栽培种杂交的亲和力最大；而栽培种类型中以天津豆（普通型）为母本与野生种杂种杂交的亲和力最大；但珍珠豆型与４个野生种杂种之间杂交的亲和力差异最小。１６个组合中有许多授粉花不能形成果针而相互间表现不同差异。果针形成正常荚果有４种败育现象。     

甘蓝型油菜与新疆野生油菜属间杂种的获得与分子鉴定

通过剥蕾重复授粉克服了甘蓝型油菜与新疆野生油菜属间杂交障碍,中双4号×野890812组合的199朵重复授粉花共产生32粒种子,其中8粒种子能发育成植株,5株植株形态与母本甘蓝型油菜相近,2株植株形态与白菜型油菜相近,1株植株形态介于母本甘蓝型油菜和父本野芥之间,叶面上具有新疆野生油菜特有的刺毛。RAPD分析显示8株F1代植株都同时具有母本中双4号和父本野890812的特征随机扩增DNA片段,还具有母父本均缺乏的新扩增DNA片段,表明8株F1代植株均为属间杂种。试验结果表明,决定甘蓝型油菜与新疆野生油菜或野芥远缘杂交中生殖隔离的主要因素是受精前障碍。属间杂种在形态和分子水平上的丰富变异预示通过甘蓝型油菜与新疆野生油菜间的属间杂交可望有效地拓展甘蓝型油菜遗传背景。     

亚麻种间杂交技术研究初报

通过对亚麻野生种和栽培种的正交、反交试验，采取重复授粉、研磨花粉重复授粉，滴注植物生长调节剂GA3、NAA、2，4-D等与授粉后子房等方法获得种间杂交种，然后把杂交种的幼苗进行组织培养、温室培育获得F1植株，在F1植株花蕾期细胞减数分裂期进行观察，并对亲本及F1代的花粉粒观察鉴定，认为所获得的杂交种属于种间杂交种，从而证明亚麻种间杂交技术取得成功。     

克服大豆种间杂种蔓生、小粒等不良性状技术的初步研究

本试验利用结荚习性不同的3个栽培大豆(G.max)作母本,以株高不同的2个野生大豆(G.soja)和2个半野生大豆(G.gracilis)作父本配制的12个杂交组合和8个回交组合,研究克服种间杂种蔓生、小粒等不良性状的技术。研究结果表明:选用植株较矮、主茎较粗、百粒重较大的有限、亚有限性栽培种作母本;选用植株较矮、百粒重较大的野生种作父本将有利于克服种间杂种蔓生、小粒等不良性状;野生亲本的选择似乎更为重要。从克服种间杂种蔓生、小粒等不良性状来看,选用半野生大豆作亲本更为有效。只有从直立、半直立植株的后代中才有可能分离出稳定的直立型材料。百粒重的遗传进度较小,对其进行选择似乎效果不明显。在F_3代进行选择性回交可以大幅度提高其后代直立、半直立型植株的分离频率和百粒重。只要亲本选配适当,仅需一次回交即可克服种间杂种蔓生、小粒的不良性状。我们从一次选择性回交的后代中已获得栽培型、百粒重20克以上,产量较高的优良品系。     

茄子杂种一代制种技术研究

为了提高华南地区茄子单位面积制种产量,以"农夫长茄"和"新丰紫红茄"的父母本为材料,研究了不同栽培季节、种植密度、重复授粉对单位面积制种产量的影响,以及不同花龄母本花授精结实能力,种果成熟度和后熟时间对种子发芽率的影响。结果表明,秋季为最适合的制种季节,早春大棚制种也可获较高的种子产量;适当密植可显著提高单位面积制种产量;母本开花当天授粉坐果率最高,次日重复授粉可显著增加种子产量;种果在授粉后55～60 d采收、后熟5～10 d取种,其种子发芽率可达到国家对茄子杂交种一级良种要求的发芽率标准。     

大豆属多年生野生种及栽培种种子蛋白质电泳分析

用SDS聚丙烯酰胺凝胶电泳(SDS—PAGE)法分析了5个多年生野生种及栽培种的种子水溶性蛋白。结果表明:各个种基本都有其特征电泳图谱。多年生野生种G.latifolia.G.microphylla及栽培种G.max的种内蛋白质图谱较为一致,而多年生野生种G.falcata,G.tabacinaG.tomentella种内蛋白质图谱则差异较大。种间蛋白质图谱比较表明:多年生野生种G.latifolia,G.micropylla、G.tabacina之间亲缘关系较近,而其他种间关系较远。野生种G.tomentella与栽培种G.max有较近的亲缘关系。     

自马铃薯二倍体栽培种(Solanum phureja)自交后代中选育诱发高频率双单倍体授粉者的研究

本试验采用了早春播种,让其植株在冷凉的气候条件下开花,并结合蕾期授粉的方法。克服了自交不亲合性,获得了3000多粒IVP35(S.Phureja)的自交种子。 1984年以东农303(雄性不育)作被测母本,用IVP35各自交后代作授粉者所作的测交结果表明,诱发单倍体的隐性基因不只1对, 因为IVP35自交后代单株无性系间诱发单倍体的频率有显著差异。本试验还选育出了优良授粉者NEA—P16和NEA—P19。按100个浆果中产生孤雌生殖的植株来计算,NEA—P16和NEA—P19诱发孤雌生殖的频率分别为IVP35的2.66和2.48倍。与优良授粉者的选育及孤雌生殖有关的问题在本论文中也进行了讨论。     

克服大豆种间杂种蔓生,小粒等不良性状技术的初步研究

本试验利用结英习性不同的３个栽培大豆作母本，以株高不同的２个野生大豆和２个半野生大豆作父本配制的１２个杂交组合和８个回交组合，研究克服种间杂种蔓生，小粒等不良性状的技术。研究结果表明：选用植物较矮，主茎较粗，百粒重较大的有限，亚有限性栽培种作母本；选用植物较矮，百粒重较大的野生种作父本利于克服种间杂种蔓生，小粒等不良性，野生亲本的选择似乎更为重要。从克服种间杂种蔓生，小粒等不良性状来看，选用半野生     

不同倍性栽培稻与药用野生稻种间杂交不结实性的比较胚胎学观察

以栽培稻(Oryza sativa)品种L202二倍体（L202 2x）及其同源四倍体（L202 4x）作母本分别与药用野生稻（Oryza officinalis）杂交,比较了两个杂交组合的杂交结实性及影响结实性的杂种胚胎发育细胞学。两个杂交组合所取得的一致结果是：杂交授粉后30 d所有杂交小穗均干枯死亡,不能结实;种间杂交不结实的原因在于受精和杂种胚胎胚乳发育异常。两个杂交组合的受精和杂种胚胎胚乳发育虽然均存在双受精、单受精和未受精类型,但就受精率而言,L202 2x作母本的平均总受精率为59.45％,略高于L202 4x（54.87％）; L202 4x的单受精率（24.60％）则高于L202 2x的单受精率（15.30％）。两个杂交组合的杂种胚胎胚乳发育均严重异常,虽然在授粉后1 d形成小的球形胚;到授粉后3 d,胚胎发育停滞并开始解体;至授粉后5 d,只有二倍体杂交组合的极少数胚胎可发育到梨形胚时期,四倍体组合的胚胎则基本全部解体。双受精胚囊内胚乳发育更为异常,在授粉后1 d,游离胚乳核就开始解体退化,到授粉后3 d不能形成细胞化胚乳或细胞化过程异常。与L202 2x作母本的杂交相比,以L202 4x作母本所得杂种胚胎发育更为滞后,且退化严重,形成的游离胚乳核少,解体早,不能进行细胞化。因此,利用同源四倍体栽培稻与药用野生稻杂交获得种间杂种的难度更大。     

甘蓝型油菜亲本基因型对其与埃塞俄比亚芥的可交配性影响

以10个甘蓝型油菜品种与埃塞俄比亚芥进行了正反杂交。结果表明,甘蓝型油莱与埃塞俄比亚芥的种间可交配性很低,但在反映可交配性强弱的各个性状上,基因型间的差异显著。甘蓝型油菜作母本时,受精频率和结角率都较反交为低,在获得杂种种子和杂种植株上明显优于反交。约2/3的甘蓝型油菜×埃塞俄比亚芥低生活力杂种种子在组织培养条件下能萌发形成植株,反交的萌发率几乎为零。甘蓝型油菜×埃塞俄比亚芥的F_1植株能与甘蓝型油菜回交,与埃塞俄比亚芥回交不亲和。由于种间杂种F_1植株群体中常出现大量的母型植株,且获得的真杂种种子出苗率又很低,因此提出以F_1杂种植株数为基准的可交配指数来衡量种间可交配性高低。     

Cytoplasmic substitution inSolanum. I. Seed production,germination, and sterilities of reciprocal backcross generations

Summary Genes ofSolanum tuberosum L. ssp.tuberosum were introduced into cytoplasm ofS. tuberosum ssp.andigena (Juz. & Buk.) Hawkes andS. phureja Juz. & Buk. to reduce cytoplasmic sterilities. Alleles that influenced berry set and seed content produced differences between reciprocal progenies. Their expressions were interpreted in terms of genes of the maternal and/or paternal parents. When the ssp.andigena genotype was introduced from the maternal parent if favoured high berry set and low seed number. Maternal ssp.tuberosum favoured lower berry set and higher seed number. The source ofS. phureja cytoplasm, aS. phureja×S. chacoense F₁, used as maternal parent favoured lower berry and seed set. During successive backcrosses progeny expressions approached those of the recurrent ssp.tuberosum pollen parents. A low level of pollen sterility occurred in BC₂ plants, unrelated to direction of cross or cytoplasmic factors. By BC₄, seed set and fertility were as good as ssp.tuberosum, and recurrent backcrossing could be terminated without loss of seed production or fertility. Pennsylvania Agricultural Experiment Station Journal Series No. 7493.     

Extra Soil Fertilization of Mother Plants Increases Botanical Seed Yield But Not Long-Term Germination in Wild <Emphasis Type="Italic">Solanum</Emphasis> (potato) Species

Potato has about 100 wild species relatives that are multiplied in the form of botanical seed populations by genebanks, and distributed for use in research and breeding, so factors that affect long term seed germination are of interest. In 1987 the US Potato Genebank conducted routine seed multiplication on 127 populations of 31 species as greenhouse-grown potted plants. Half of the parent plants in each population were given two doses of liquid fertilizer in addition to the standard slow-release granular fertilizer which had been mixed into the medium for all plants. Plants with this extra liquid fertilizer application grew larger, and produced significantly more fruit and seeds. However, seeds from parents fertilized extra did not have improved seed weight or germination after 26 years of storage. We conclude that optimizing the fertilizer regime used on parent plants, while doubling the average seed yield, does not result in higher quality seeds.     

杂交稻杂株的表现型及保纯对策

根据５６２份样品的海南纯度鉴定，从遗传学角度把杂株的表现型分为当代表现型、隔代表现型、多代表现型、变异表现型等四类，并提出了防杂保纯的对策．     

The identification and evaluation of hybrid plants among open pollinated tkue seed families

An increase in the proportion ofhybrid vs. selfed plants improves the performance ofopen pollinated (OP) true potato seed (TPS) families. Strategies to increase the proportion ofhybrid seeds were investigated. A marker gene for yellow tuber flesh in a diploid clone, interplanted as the male parent, permitted identification of 4x × 2x hybrids among the OP progeny. Only 5% of the OP progeny were 4x × 2x hybrids. The proportion of 4x × 2x hybrid plants among the OP progeny was increased when the female parent had low male fertility and when only the largest 25% of the seeds were planted. The hybrid 4x × 2x plants were superior for all traits evaluated on the OP seedling transplant families. Traits included vigor, flowering, pollen stainability, OP fruit set, and tuber yield. Effects of the female parent were significant only for vigor and flowering, while seed size did not affect values for any trait consistently: With the limited outcrossing observed, the low seed set obtained when using parents with low male fertility and the work involved in selecting the largest seeds within individual fruits were not justifiable. However, research with OP true seed families asa low cost planting material should be continued, since high yielding OP families have been identified.     

Reduction of Seed Dormancy in Echinacea pallida (Nutt.) Nutt. by In-dark Seed Selection and Breeding

Strong seed dormancy has been an obstacle for field production of Echinacea species. Previous research on overcoming Echinacea seed dormancy has been extensive and focused on treatment methods, which involve time and expense, and are incompatible with organic production if synthetic chemicals are used. We have attempted to genetically reduce seed dormancy through selection and breeding in Echinacea, by using Echinacea pallida as a model species. Three accessions were used in this study. Nine parent plants of each accession selected from early, in-dark germinated seeds (in-dark plants) or from late, in-light seeds (in-light plants) were planted and grouped by accession and germination treatment method for seed production through a polycross method. Germination tests indicated that these in-dark plants produced seed (in-dark seed) with significantly reduced seed dormancy when tested under light or dark condition in comparison to the seed of the in-light plants (in-light seed). Among the three accessions, the in-dark seed germinated at much higher rates than did the in-light seed, more than 2× at 25 °C under light and up to an 83× increase in darkness, and up to an 8× increase over the corresponding parental seed lots under comparable germination conditions. In addition to these increases in germination, the in-dark seed showed early and synchronized germination as compared to the in-light seed. Since these results were achieved through only one cycle of selection and breeding, they strongly suggest that we have developed a very effective method for modifying seed dormancy in Echinacea.     

抗除草剂基因导入培矮64S实现杂交水稻制种机械化的初步研究

 利用农杆菌介导的高效遗传转化技术，成功地将Bar基因转入两系杂交稻的不育系培矮64S。转基因植株具有明显的Basta抗性，分子检测进一步证明Bar基因已整合到水稻染色体上。模拟制种的成功，表明机械化制备杂交水稻种子是可行的。讨论了实现机械化制备杂交水稻种子所需解决的各种问题。     

杂交籼稻亲本种子休眠性与F1的相关及配合力研究

 利用19个核质互作型不育系和9个恢复系,配制了109个杂交组合。花后35 d收获种子,分别检测每个杂交组合F1及其亲本种子在不剥壳和剥壳情况下的休眠指数。采用5×5 NCⅡ遗传设计配制了25个组合,利用其种子的休眠指数分析了配合力。结果表明,在不剥壳情况下,F1种子的休眠指数与双亲种子的休眠指数以及中亲值呈极显著正相关。109个组合中,82个组合超过中亲值,43个组合超过高亲值,具有明显的中亲优势。去除稃壳的双亲及F1种子的休眠指数均大幅度下降,表明稃壳对种子休眠性具有重要作用,但剥壳后双亲种子和F1种子休眠性之间的关系,仍然存在与不剥壳时相似的趋势。稃壳对种子休眠性的影响主要取决于F1的基因型,而不受控于母体稃壳本身。不育系、恢复系休眠性的一般配合力方差和组合的特殊配合力方差占总遗传方差的比例分别为59.2%、31.1%和9.7%,三者均达到极显著水平,说明基因的加性作用占主导地位。不育系Ⅱ112A 种子休眠性的一般配合力最高,D62A次之;恢复系以IR112一般配合力最高,2786次之。它们是选配强休眠杂交组合的优良亲本材料。     

Ineractions between a mild and a severe strain of potato spindle tuber viroid in doubly infected potato plants

Potato (Solarium tuberosum) plants co-infected with a mild and a severe strain of potato spindle tuber viroid (PSTVd) were analyzed by return-polyacrylamide gel electrophoresis for the presence of both strains in vegetative and reproductive plant parts. Both strains were detected in the anthers, flowers, inflorescences, leaves, ovaries, ovules, petals, pistils, roots, sepals, stolons and tubers. Only mild strain was detected from pollen in the cultivars tested. True potato seed (TPS) were not doubly infected when they were obtained from co-infected maternal parent plants pollinated with pollen from healthy plants. Also, when maternal plants infected with severe strain were pollinated with pollen from healthy plants or from those infected with the mild strain, TPS were not doubly infected. A small number of TPS with double infection was obtained when co-infected or mild-strain-infected plants were pollinated with pollen containing the severe strain (singly or doubly infected). The number of TPS containing mild strain predominated in a ratio of 7:1 over TPS containing the severe strain. This study indicates that segregation of strains from doubly-infected plants probably takes place during pollen formation and persists through seed development.     

花生种子脂肪含量的直接和母体遗传效应分析

种子脂肪含量是花生的重要经济性状。本研究旨在通过分析花生脂肪含量遗传的直接效应和母体效应，为高脂肪含量新品种选育、分子标记开发及基因组选择策略的确定提供依据。选用不同脂肪含量的中间型花生品种豫花9326及潍花6号，龙生型农家品种永城小麻壳，珍珠豆型品种湛油62及泉花6号，配置完全双列杂交组合，索氏残渣法分析5个亲本、20个杂交组合的F1和F2等3个世代种子的脂肪含量，利用广义遗传模型分析脂肪含量遗传的种子胚基因直接效应、母体效应及其遗传力。研究结果表明，双亲之一具有较高脂肪含量，另一亲本具有中等以上脂肪含量，则F1的脂肪含量较高；双亲脂肪含量中等，或者亲本之一脂肪含量较低，则后代脂肪含量较低。种子直接加性效应方差最大，其次为母体加性效应，母体显性效应的方差较小，种子脂肪含量无细胞质效应。种子直接效应的遗传力大于母体效应。高脂肪含量亲本的直接加性效应正值较大，低脂肪含量亲本的直接加性效应的负值较大，中间脂肪含量亲本的直接加性效应数值基本居中，方向有正有负。本研究表明脂肪含量的遗传主要受种子自身基因型的加性效应控制，其次是母体加性效应，无细胞质效应。高脂肪含量花生品种豫花9326和永城小麻壳是优良的高脂肪含量供体亲本。挖掘种子脂肪含量关键调控基因应该兼顾荚果皮中表达基因对种子脂肪含量的调控作用。杂交后代选择及分子标记开发应注重基因的累加效应和优良单倍型的选择。