植物胚败育机理及其离体培养挽救技术之研究进展

从植物胚胎败育机理及影响植物胚胎离体挽救成功的因素两个方面综述了近些年来有关植物胚胎败育的研究进展。从器官发育、生理生化指标及遗传的角度看,引起植物胚胎败育的主要原因有七类：胚囊发育异常、胚乳发育异常、幼胚起源、营养供应失调、内源激素、酚类物质、某些酶的活性变异及基因调控。由于胚胎败育原因的多样性,增加了胚挽救的难度。文章还讨论了影响植物胚胎挽救成功与否的主要因素包括胚挽救材料及处理方式、胚龄、培养基种类及培养条件、渗透压、添加剂。在分析上述败育原因和挽救因素的基础上,讨论了未来植物幼胚败育研究的可能方向和挽救技术上仍存在的问题。     

普通小麦与六倍体小黑麦杂交不亲和性的研究 Ⅰ.杂种的胚胎发育

本文对普通小麦与六倍体小黑麦这一组远缘杂交的不亲和性,从胚胎学的角度进行了研究。以六倍体小黑麦作母本,杂种胚胎发育与亲本的差异较小;以普通小麦作母本,杂种胚发育逐渐表现出显著的异常,最终是胚败育,种子失去生活力。通过对胚的切片的解剖观察和胚离体培养的研究,表明在以普通小麦作母本的杂交种子中,胚乳的发育异常发生在胚败育之前,及时将胚取出作离体培养可以发育成苗,因而证明胚的败育是由胚乳的异常发育引起的。本文讨论了这些杂交种子中胚乳发育的不同情况对胚的不同影响。     

枣胚败育因素分析及提高幼胚发生的措施

枣胚退化或败育特性是枣树杂交育种的重要障碍。本文重点介绍了枣胚败育类型及特征、胚败育的生理与分子机制,提出了诱导幼胚合成内源激素以及利用胚挽救技术等提高幼胚发生的措施,为进一步深入探索枣胚败育的分子机制以及枣树杂交育种提供一定的理论参考。     

特晚熟红桔JZT(P)-1胚珠败育的胚胎学研究

为进一步探明晚熟无核红桔的无核机理,为晚熟柑橘种质资源的开发利用提供可靠的科学依据,以特晚熟无核红桔JZT(P)-1为实验材料,采用直接解剖、连续石蜡切片、显微技术等方法重点对其胚珠败育过程进行系统的观察研究。结果表明,JZT(P)-1胚珠中的孢原细胞、胚囊原始细胞以及不同发育程度的胚囊基本上都败育,极少数胚珠发育成为健康的种子。在幼果前50天的发育中,胚囊原始细胞多起源发育,发生时间紊乱,使得珠心中早期孢原细胞及不同发育期胚囊的正常发育受到干扰,促使胚珠中各雌性结构的败育。幼果中雌性败育率极高,通过石蜡切片观察到正常胚的发育十分困难。基本成熟的果中,种子数0~4粒,平均种子数(1.3±0.42)粒,经济无核率高达100%。正常种子多胚。研究结果为探明特晚熟红桔新种质JZT(P)-1的无核机理提供了胚胎学证据。     

植物胚败育相关基因研究进展

种胚败育在许多植物中普遍存在并一直是研究的热点，但种胚败育机制尚不明确。为探寻植物胚胎败育分子机制，本文在介绍植物胚发生过程的基础上，重点阐述了种胚败育的相关基因及基因表达研究方面的进展情况。当前植物胚胎发育的调控基因互作、协同机制尚不清楚，今后应运用多组学加大从基因调控到信号传导过程的深入研究，并对植物胚胎败育分子机制的研究进行了展望。     

同源四倍体水稻亚种间杂种胚囊的结构及受精特点

利用激光扫描共聚焦显微术对11份同源四倍体水稻亚种间杂种的胚囊结构和双受精特点进行研究,结果表明,所有四倍体杂种均存在一定频率的败育胚囊,败育频率因组合而异,最高的败育率为23.8%,最低为5.5%,平均14.3%。败育胚囊主要有胚囊退化、异常小胚囊、无卵器、无雌性生殖单位和极核位置异常等5种类型。杂种在双受精过程     

我国特有珍稀花卉植物蝟实生殖生物学特性研究

通过用石蜡切片、扫描电子显微镜以及数量统计与分析的方法,研究蝟实大孢子发生及其雌配子体发育的特征;种子发育特点以及种子在果实中发育的数量变化.结果表明:其胚珠倒生,薄珠心,单珠被,大孢子四分体呈直线排列,功能大孢子位于合点端.胚囊发育类型属于蓼型.婿实的胚胎学特征与忍冬科的胚胎学特征基本相同;在植株上种子胚的发育停留在鱼雷型胚时期,这属于种子的后熟现象.得出的结论是:蝟实胚发育停留在鱼雷型胚时期,种子发育不完全及败育率非常高(61.86%)是影响蝟实繁育的主要内因,也是蝟实稀有及孤岛状分布的原因.     

红宝石无核葡萄胚发育及败育的观察

以种子败育型葡萄红宝石无核为试材,采用石蜡切片法系统观察其胚发育及败育进程.结果表明,红宝石无核胚能发育到心形胚阶段,随后胚逐渐败育,胚珠不能继续发育为成熟种子.红宝石无核的胚乳败育早于胚败育,其胚挽救适宜取材时期是花后40天.     

华北驼绒藜种子发育过程中内源激素变化动态的研究

以3种结实类型华北驼绒藜的种子(正常发育型,轻度败育型,高度败育型)为材料,对种子发育过程中内源激素含量动态进行了观察测定.结果表明:正常发育型华北驼绒藜种子IAA和GA,含量随着种子的发育呈持续上升趋势,轻度败育型和高度败育型种子IAA和GA3含量在种子发育初期(花后10 d)同时出现明显下降,随后开始上升;ZR含量在种子发育过程中呈单峰曲线,败育型种子的ZR含量要显著低于正常发育型;ABA含量在种子发育前期较低,随着种子的发育呈上升趋势,但3种结实类型种子间的差异并不是很大;在种子发育初期(花后10 d),正常发育型与两种败育类型种子(IAA GA3 ZR)/ABA的比值差异达到最大,说明内源激素动态变化及它们之间的比例平衡关系与华北驼绒藜胚胎败育有着密切联系.     

光敏感雌性不育苎麻的光周期反应特性研究

光周期敏感雌性不育苎麻(PFSR)头、二、三麻均能成花, 但头、二麻雌性败育, 三麻雌性可育, 雄性发育正常, 年度间表现稳定. 对其光周期特性研究分析表明: (1) 6至7月, PFSR雌性育性转换的临界日长在13.0 h/d至13.5 h/d之间, 败育发生早而彻底; (2) 经SD+LD和LD+SD处理, 雌性表现为相邻节位间由可育到不育或不育到可育的跃变,     

Reproductive barriers in the intergeneric hybridization between <Emphasis Type="Italic">Chrysanthemum grandiflorum</Emphasis> (Ramat.) Kitam. and <Emphasis Type="Italic">Ajania przewalskii</Emphasis> Poljak. (Asteraceae)

In order to reveal the causes of low seed set in the intergeneric cross between Chrysanthemum grandiflorum (Ramat.) Kitam. ‘Zhongshanjingui’ (female parent) and Ajania przewalskii Poljak. (male parent), we systematically investigated megasporogenesis and megagametogenesis of female parents, pollen germinability of male parents, pollen–pistil interaction and hybrid embryo development using paraffin section and light, fluorescence and scanning electron microscopy. The results indicate that development of megagametophyte of female parent belongs to Polygonum type and 84.6% ovules developed to normal 8-nucleate embryo sac at the stage of pollination; the pollen germinability in vitro of male parent was 39.3%; a large number of pollen grains germinated normally and no callose deposited on the female stigmas within 24 h after pollination. Furthermore, about 75% ovules were fertilized, whereas only 17.2% ovules developed to normal maturing embryos at 15 days after pollination due to abortion at various developmental stages. Taken together, these results suggest that sterile ovules of female parent, pollen viability and pollen–pistil interaction have no significant influence on seed set in the cross. A high percentage of embryo abortion or degeneration, i.e. post-fertilization barrier, may be the main factor for low seed yield.     

花生种间杂种胚胎发育及内源激素变化

以花生栽培品种豫花15为母本分别与野生种A. correntina和A. macedoi杂交,以栽培品种间杂交组合豫花15×白沙1016为对照,采用石蜡切片技术观察花生杂种胚胎发育进程,酶联免疫吸附分析法(ELISA)测定花生杂种胚胎内源激素含量, 分析胚胎发育进程与胚胎内源激素含量的关系。结果显示,3个杂交组合的下针率无明显差异,表明栽培种与2个野生种杂交不存在受精前障碍;与对照相比,豫花15×A. correntina表现杂交可亲和,其胚胎发育中激素含量的变化与对照组合基本一致;而豫花15×A. macedoi杂交授粉后12 d内胚胎发育基本正常,17~27 d发育缓慢,之后珠被迅速向内增生抑制了胚的进一步发育并最终败育,在同一时期的杂种胚胎中,3-吲哚乙酸(IAA)、赤霉素(GA₃)和玉米素核苷+二氢玉米素核苷(ZR+DHZR)等促进生长的激素维持在较低的水平,而脱落酸(ABA)含量以及脱落酸与某一促进生长激素或3类促进生长激素之和的比值保持了较高的水平,推测可能是激素代谢的失衡导致种间杂种胚胎的败育。用IAA、激动素(KT)单独或混合处理不亲和组合豫花15×A. macedoi杂交授粉后的果针基部表明,外施促进生长的激素能够明显增加胚珠的长度,一定程度上验证了上述推测。     

田间喷施生长调节剂对冬枣胚发育及坐果的影响

摘 要：以轻度败育枣品种冬枣为试材,在盛花期进行不同种类、不同浓度生长调节剂（GA3、IAA、6-BA）的喷施试验,旨在明确外源生长调节剂对枣胚发育和坐果的影响。结果表明,盛花期喷施不同浓度6-BA（50 mg/L～150 mg/L）可有效提高冬枣小果含仁率至100%（对照91.1%）,同时坐果率可达18.3%（对照7.3%）;而喷施GA3、IAA却不同程度上降低了冬枣含仁率,但果实坐果率明显提高分别为69.3%（对照17.0%）、45.8%（对照14.6%）。     

Cultivar variation for seed development in white clover (Trifolium repens L.)

Summary A controlled environment study was undertaken to clarify the factors responsible for poor seed set and to study seed development, ovule degeneration and seed abortion, both morphologically and cytologically, in three Japanese cultivars of white clover. Although the mean number of ovules per floret was 4.2–5.1, the average number of seeds per floret was found to be only 2.3–2.7. Microscopic examination of carpels from 0 to 28 days following floret maturity and pollination showed that 26–33% and 8–17% of the total seeds lost occurred within the first three days and the third through fifth day following pollination, respectively. Beyond this period occasional seed abortion was observed at all stages of seed development, but this represented a very small proportion (2–7%) of the total seeds lost.A stain clearing technique was used to examine the cytoplasmic state of the embryo sac in intact, unfertilized, mature ovules and embryos of the ovules at 3 and 5-day periods following pollination. It was found that 20–22% of unfertilized and matured ovules were sterile, suggesting that ovule degeneration before fertilization was the major cause for the high percentage of seeds lost within a 0 to 3-day period following pollination. Cytological observations revealed that abortion of developing seed was due to a sudden arrest in embryo growth and that the early development of the embryo of such aborting seed was normal. Either nutrient shortage or meiotic irregularities may be the cause for high ovule sterility or post-fertilization abortion of developing seeds.     

美洲南瓜远缘杂交亲和性研究

选取南瓜属3个主要栽培种29个材料并选配了大量杂交组合,结果表明：美洲南瓜与中国南瓜或印度南瓜进行种间杂交,美洲南瓜只适合作为父本;中国南瓜或印度南瓜的不同试材作为母本与美洲南瓜杂交,存在亲和性差异,表现在坐果率、单果种子数、种子发育程度以及有胚果实率等方面的不同;美洲南瓜种内变种间不存在生殖隔离,可通过相互杂交融合目标性状。试验总结出杂交授粉时间在上午6:30至8:30,采用全程防虫网覆盖、吊蔓栽培技术,可提高坐果率并延长种胚发育时间,改善南瓜属远缘杂交亲和性。     

华山松种子园花粉管理的技术研究

从1986年起,我们对平坝华山松幼龄林种子园进行开花习性,人工辅助混合授粉和施肥促进开花的研究。研究结果表明,幼龄林种子园具有一定的结实能力,开雌花株数达45.5%。但是雌球花败育率高(73%),有雄花株少(12%),着果率低(59%)。通过人工辅助混合授粉,可提高着果率16.7%,施肥可增加雄球花花数1倍以上。     

Reduction in the yield and viability of carrot seed in relation to the occurrence of the plant bug Lygus campestris L.

Summary Research was carried out into the cause of a disorder occurring in seed plants of carrots characterized by backward fruits and resulting in a reduced seed yield.It appeared that both fertilization and initial development of the endosperm and embryo were normal, but that later on a sudden check in the growth of the fruit occurred, accompanied by disintegration of the contents of the ovule.Bugs of the species Lygus campestris L. were found to occur in considerable numbers on the seed plants of carrots. In experiments a reduced seed production with the same macroscopic and microscopic symptoms could be obtained when bugs were added to caged carrot umbels.It could be established that the presence of bugs caused not only a reduction in the seed production due to abortion of endosperm and embryo, but also a reduction in the germination percentage of the full-grown seeds due to embryolessness.When the bugs were brought on the umbels before or during anthesis the reduction in seed viability and expecially the reduction in seed production proved to be more serious than when the bugs were added after anthesis.     

陆地棉三体的诱发、鉴定及其利用研究──Ⅲ雌配子发育的胚胎学观察

对３个三体（Ｆｔｒ－２，Ｆｔｒ－４和Ｆｔｒ－５），两个四体（Ｆｔｅ－４和Ｆｅｔ－５）成熟胚囊结构的胚胎学观察以及秕子率的统计分析表明，所有材料均有不同程度的胚囊败育，但不同的材料胚囊败育时期不同，Ｆｔｒ－２和Ｆｔｒ－５胚囊败育主要发生在双核胚囊期以前，Ｆｔｒ－４，Ｆｔｒ－５和Ｆｔｅ－４各时期都有一定的败育率。胚囊败育是造成Ｆｔｒ－２和Ｆｔｒ－５雌配子传递率低的主要原因，Ｆｔｒ－４雌配子传递率低是胚囊败育和幼胚败育两方面因素共同作用的结果。