乌丹蒿开花动态、花粉活力及柱头可授性研究

在科尔沁沙地西部地区选取长势一致乌丹蒿植株,定株观察其开花动态和花后柱头的形态变化,并用TTC法检测花粉活力,用联苯胺—过氧化氢法检测其柱头可授性。结果表明:乌丹蒿整体开花格局是从上至下,头状花序内的小花是由外向内逐次开放,头状花序开花持续时间为3~7d,单株花期最长时间为19d;花粉寿命长达4d,在开花后第3d花粉活力最高,为47.12%;最佳授粉期为开花后3~4d;柱头可授性时间为6d,边缘花开花后第3d柱头的可授性最强;乌丹蒿花粉活力最高期与柱头可授性最佳期同时进行。     

玉米C群不同亚群雄性不育胞质对小斑病（Bipolaris maydis）C小种侵染的病理反应研究

以１０套同核异质（Ｎ、Ｃ、Ｒｂ、ＥＳ）品系及Ｃｍｓ－Ｃ胞质背景的３个杂交种（Ｆ１）为试材．对田间观测的４个病理指标的鉴定和分析结果表明：（１）除乳熟期病情指数外，其余３个病理指标的结果显示出Ｃ小种对Ｃ群ＣＩ亚群雄性不育胞质具有专化性侵染的特点．但在不同病理指标、不同核型之间所表观的专化性程度却有较大差别；ＣⅡ、ＣⅢ亚群胞质无专化侵染现象．（２）Ｃ小种的致病力小于Ｔ小种．     

矮败小麦开花习性与异交结实率的研究

矮败小麦的花器结构和开花习性与太谷核不育小麦相似。柱头生活力长达１０天。不育株的抽穗期较可育株晚２－５天。株高反及可育株的二分之一至三分之二。可育株顶部１－２片叶隔其花粉降落，减少不育株柱头接受花粉的机会，其异交结实率低，平均仅为４０－５０％。     

响应面法优化玉米须中芦丁的提取工艺及检测

为探讨玉米（Zea mays）须中芦丁提取工艺和检测条件,本试验选取乙醇体积分数、液料比、回流时间和超声时间4个因素,采用响应面法优化玉米须中芦丁的提取工艺,并将最佳工艺条件提取的芦丁样品进行紫外光谱和红外光谱测定。结果表明,玉米须中芦丁的最佳提取工艺条件为乙醇体积分数49%、液料比30 mL∶1 g、回流时间1.7 h以及超声时间36 min。在该工艺条件下,玉米须芦丁含量为12.152 mg·g-1,且经紫外、红外光谱测定,其主要官能团吸收峰显著,HPLC检测重现性好。说明该工艺对玉米须中芦丁的提取优化效果显著,为玉米须深层次研究提供了一定参考。     

钝裂银莲花花部综合特征及其繁育系统

钝裂银莲花(Anemone obtusiloba)是青藏高原东部常见的一种优势毒杂草,也是一种重要的草原退化指示植物,目前对其繁殖特性研究甚少.通过野外定位观察,运用TTC法、联苯胺-过氧化氢法、花粉-胚珠比(P/O)、杂交指数、人工授粉和套袋试验等方法,首次对该物种的花部特征及繁育系统进行了研究.结果表明:该物种单花花期为4～5 d,花雌雄异熟,雌蕊先熟,单花花粉活力和柱头可授期之间也存在一段时间的重叠,钝裂银莲花最佳授粉时间为一天中的12:00-14:00左右;按照杂交指数,其繁育系统属于异交、部分自交亲和,需要传粉者;P/O约为86,判断繁育系统类型为兼性自交;套袋试验显示,钝裂银莲花自然条件下存在无融合生殖现象,繁育系统为自交、异交亲和,以自交为主,但有时也需要传粉者;由此推断,该物种的繁育类型为混交的交配系统,即自交和异交并存,但倾向于自交.在长期的环境选择压力下,钝裂银莲花倾向于自交,可能是对不利环境条件的一种适应进化策略.     

广东省甜玉米小斑病菌的生理小种鉴定

摘 要：从广东省甜玉米主产区采集了4个有代表性的小斑病标样,分离提纯病原菌,通过扫描电子显微镜观察玉米小斑病菌的孢子,并结合病菌生物学特性,对分离出的4个甜玉米小斑病菌株进行了生理小种的鉴定。结果表明：4个甜玉米小斑病病原菌的孢子形态和生物学特性完全一致,符合O小种特征,因此认为广东省甜玉米主产区的小斑病病原菌是同一生理小种类型（O型）。     

玉米黑粉菌基因组编码蛋白作用位点的计算机预测

利用已公布的玉米黑粉病菌基因组全序列数据及信号肽预测软件SignalP v3．0、亚细胞器中蛋白定位分布预测软件TargetP v1．01、跨膜螺旋结构预测软件TMHMM v2．0和膜锚定位点预测软件Big-PI Predictor预测分析了玉米黑粉病菌基因组编码蛋白的作用位点。结果表明,在6522个ORF中,具有分泌功能的有543个,占全基因组基因总数的8．3％;作用位点在线粒体的有1552个,占全基因组基因总数的23．4％;具有跨膜结构的有1269个,占全基因组基因总数的19．5％;锚定在膜上的有56个,占全基因组基因总数的0．9％。     

Enclosed stigma contributes to higher spikelet fertility for rice(Oryza sativa L.) subjected to heat stress

With global warming, rice plants may be subjected to heat stress more regularly during the heatsensitive flowering stage, causing spikelet sterility and grain yield loss.Stigma exsertion is considered to increase pollen reception and promote female reproductive success.The aim of this study was to investigate the role of stigma exsertion on spikelet fertility at high temperatures.Five rice cultivars(Liangyoupeijiu, Shanyou 63, Huanghuazhan, Nagina 22, and IR64) with differing degrees of stigma exsertion were cultivated and exposed to high temperature at anthesis.Heat-tolerant cultivars did not always show a high percentage of spikelets with exserted stigmas, and vice versa.Irrespective of the presence of more pollen grains on exserted stigmas, spikelets with exserted stigmas did not show greater spikelet fertility than spikelets with fewer exserted stigmas or hidden stigmas under heat stress.GA3 application augmented the percentage of spikelets with exserted stigmas;however, it did not increase spikelet fertility under heat stress.Spikelet fertility of whole panicles was negatively correlated with the percentage of spikelets with exserted stigmas, but positively with that with hidden stigmas.Viability of the hidden stigmas was less reduced than that of exserted stigmas under heat stress, suggesting that hidden stigmas have an advantage in maintaining viability.Heat stress delayed anther dehiscence and reduced the viabilities of both exserted stigmas and pollens, thereby causing low spikelet fertility.Together, these results suggest that high spikelet fertility does not depend on stigma exsertion and that enclosed stigma generally contributes to higher spikelet fertility and heat tolerance under high-temperature conditions during flowering in rice.     

Genetic Improvement and Biological Characteristic Analysis of Dwarf Abortive Type Japonica CMS Lines with Wide Compatibility

From the view of methodology for genetic improvement ofJaponicacytoplasmic male sterile(CMS) lines,we introduced the breeding process of the dwarf-abortive type(DA type)JaponicaCMS line Chunjiang 95A with wide compatibility,and further investigated the biological characteristics of the DA type Chunjiang 95A and its isonuclear alloplasmic CMS line Dian-I type Chunjiang 95A.The results show that DA type Chunjiang 95A is a japonicalinous CMS line and mainly typical abortive,which is better in fertility stability than stained abortive typeJaponica CMS lines.The DA type Chunjiang 95A is featured with high stigma exsertion,good flowering habit,high outcrossing rate and wide compatibility.Its recoverability differs from stained abortive typeJaponicaCMS lines.Moreover,we discussed genetic improvement of the typical abortive type JaponicaCMS lines and the application prospects of heterosis.