广聚萤叶甲地理种群间交配选择及子代的发育表现

为探究分布于我国不同地域的广聚萤叶甲(Ophraella communa)种群之间的分化现状,本文对来自南京、长沙和福州等3个地理种群的交配选择行为及杂交后代发育表现进行了研究.结果表明,在试验观察的6 h内南京种群与福州种群间个体发生交配的概率显著低于对照(种群内雌雄个体间的交配),但南京种群与长沙种群个体间发生交配的概率与对照无显著差异;南京和福州种群的雄性与同种群雌性交配选择次数显著多于与异种群雌性交配的次数,但南京与长沙种群间个体交配的次数与对照无显著差异.3个地理种群间个体杂交后代在卵孵化率、幼虫化蛹率和成虫羽化率等发育特性上与对照(种群内个体自交)无显著差异.根据研究结果推测,广聚萤叶甲南京种群与福州种群间在个体交配行为上存在着一定程度的交配前隔离.     

芥菜型多室油菜与甘蓝型油菜的种间远缘杂交

通过对芥菜型多室油菜与甘蓝型油菜种间杂交 以下简写为芥×甘或甘×芥 的结实性、交配性以及不同甘蓝型油菜对交配性的影响等研究发现:芥、甘正反交形成的饱满种子数较少,其形成种子的能力弱,但是芥×甘与甘×芥杂交相比,芥×甘形成饱满种子的能力较强,受精能力以及杂种胚胎的发育能力也强,在授粉后的子房发育上二者无显著差异.所以,芥菜型多室油菜与甘蓝型油菜种间杂交创建新资源时宜采用芥×甘杂交方式;不同甘蓝型油菜品种与芥菜型多室油菜正反交的结角率、受精指数、结籽指数和可交配指数均不相同,但可交配指数的变异系数最大.因此,筛选可交配性强的甘蓝型基因型应着眼于可交配指数高的甘蓝型油菜亲本材料,根据本试验结果,芥菜型多室油菜与甘蓝型油菜93-221-1杂交形成的杂种胚具有较强的可发育性.     

鹅掌楸不同交配组合子代遗传多样性分析

揭示不同交配类型与子代遗传多样性的关系, 对于林木杂交育种及种子园管理具有理论与实践意义。文章选取来自鹅掌楸、北美鹅掌楸及杂交鹅掌楸的16个交配亲本, 共组配14个杂交组合, 分属5种交配类型, 分别为种间杂交、种内交配、多父本混合授粉、回交、以及自交。每个交配组合随机抽取30个子代, 利用SSR分子标记检测各子代群体遗传多样性以及16个交配亲本间的遗传距离。结果表明, 总体上, 鹅掌楸交配子代群体具有较高的遗传多样性。5种交配类型子代群体中, 遗传多样性水平由高至低的趋势为: 多父本混合授粉子代、种间交配子代、杂种F1与亲本的回交子代、种内交配子代, 自交子代。子代遗传多样性与亲本间遗传距离呈显著正相关, 表明亲本间遗传距离大, 则子代遗传多样性高。相同亲本正反交子代群体的遗传多样性差别不明显。     

青海省药用植物龙葵栽培前后光合特性的比较

为了揭示青藏高原地区药用植物龙葵栽培前后的光合生理特性,本文采用常规光合指标测定方法对青海省药用植物龙葵栽培前后光合特性进行比较研究.结果显示:(1)野生龙葵的Chla、Chlb和Chlt含量低于栽培龙葵的,其中两者Chla含量间存在显著差异(P＜0.05),Chlb和Chlt含量间差异极显著(P＜0.01);(2)野生龙葵的Car、Chla/Chlb、Chlt/Chlt则明显高于栽培的,其中Car、Chla/Chlb间存在显著差异(P＜0.05),Car/Chlt间差异不显著(P＞0.05);(3)野生和栽培龙葵的净光合速率日变化类型均为双峰曲线型,但总体趋势表现为野生龙葵的低于栽培龙葵的;(4)相关分析表明,光合有效辐射与Pn间呈极显著负相关关系,相对湿度与Pn间呈极显著正相关关系,细胞间隙CO2浓度、气温与Pn呈显著负相关关系,瞬时水分利用效率与Pn间呈显著正相关关系.研究表明,栽培前后抗性生理指标的变化是青藏高原低温、低气压、强辐射等多种逆境生态因子长期作用的结果,是植物对生态环境的一种生理性适应.     

香菇野生菌株线粒体DNA多态性

利用PCR技术扩增了我国 7个省的 2 0个野生香菇菌株的线粒体DNA的 2个小区段 ,利用限制性酶切技术研究这 2个片段长度多型性 (RFLPs) ,结果显示 ,2 0个野生香菇菌株间的线粒体DNA在研究的区段上分为 2大类型 ,相似性为 70 % ,与栽培种相比存在较大的遗传差异。     

寄主型和迁飞型棉蚜的交配行为

棉蚜Aphis gossypii Glover种群存在寄主利用和迁飞能力上的明显分化,有棉花型和瓜型、迁飞型和滞留型之分。但是,棉花型与瓜型之间,以及迁飞型与滞留型之间是否能发生交配行为,尚无研究报道。本文在低温和短光照条件下分别诱导棉花型、瓜型、迁飞型和滞留型棉蚜的性蚜,并进行性蚜间的交配行为观察。结果表明,迁飞型和滞留型性蚜间可以发生交配行为,杂交时发生交配行为的个体比率与自交时无显著差异,但是杂交时雄蚜寻找配偶所花的时间要显著长于自交时,并且迁飞型雌蚜(M♀)与滞留型雄蚜(S♂)杂交时的交配持续时间也显著长于自交时。迁飞型和滞留型棉蚜同型交配容易完成,棉蚜的迁飞型和滞留型已在交配行为上产生了一定的分化。棉花型和瓜型棉蚜的性蚜间可以发生交配行为,并且两品系在正交和反交时雄蚜的寻偶时间与交配持续时间均无显著差异。     

Mating behaviour of host-specialized and migratory biotypes of the cotton aphid

棉蚜Aphis gossypii Glover种群存在寄主利用和迁飞能力上的明显分化,有棉花型和瓜型、迁飞型和滞留型之分.但是,棉花型与瓜型之间,以及迁飞型与滞留型之间是否能发生交配行为,尚无研究报道.本文在低温和短光照条件下分别诱导棉花型、瓜型、迁飞型和滞留型棉蚜的性蚜,并进行性蚜间的交配行为观察.结果表明,迁飞型和滞留型性蚜间可以发生交配行为,杂交时发生交配行为的个体比率与自交时无显著差异,但是杂交时雄蚜寻找配偶所花的时间要显著长于自交时,并且迁飞型雌蚜(M ♀)与滞留型雄蚜(S♂)杂交时的交配持续时间也显著长于自交时.迁飞型和滞留型棉蚜同型交配容易完成,棉蚜的迁飞型和滞留型已在交配行为上产生了一定的分化.棉花型和瓜型棉蚜的性蚜间可以发生交配行为,并且两品系在正交和反交时雄蚜的寻偶时间与交配持续时间均无显著差异.     

亚洲栽培稻与AA染色体组稻种的可交配性及F1杂种育性分析

从可交配性和F1杂种育性两方面对亚洲栽培稻与AA染色体组（以下简称AA组）其他7个稻种的系统关系进行了分析。结果表明：栽培稻籼、粳亚种与AA组不同稻种杂交均具有一定的结实率,可交配性不是影响亚洲栽培稻与其他AA组稻种间基因交流的主要生殖障碍。亚洲栽培稻与普通野生稻及尼瓦拉野生稻种间F1花粉育性和小穗育性有不同程度分化,与其他稻种的F1花粉育性和小穗育性均很低,F1杂种不育是AA组内基因交流的主要障碍。综合可交配性和F1小穗育性两方面的因素,初步得出：亚洲栽培稻与AA组稻种的亲缘关系由近及远依次是：普通野生稻、尼瓦拉野生稻、南方野生稻、展颖野生稻、非洲栽培稻、长雄蕊野生稻和短舌野生稻。其中普通野生稻和尼瓦拉野生稻是AA组中可直接利用于水稻育种的野生稻资源。     

表型与亲本不易区分的茯苓同核体菌株新类型

茯苓Wolfiporia hoelen是我国传统中药材之一,也是一种食药兼用的大型真菌,目前已规模化栽培,但由于其交配系统一直不明确,影响了种质改良。前期我们发现了茯苓的同核体,明确了茯苓的交配系统和生活史,并建立了以培养特性和分子标记区分同核体的方法,但未明确是否适用于茯苓种群的不同个体。在对多个菌株的研究中,发现了同核体表型与亲本不易区分的茯苓菌株。本研究主要以来自日本的菌株775 (NBRC 30628)为亲本,对其同核体菌株进行收集鉴定,并对同核体菌株的培养特性、交配现象和杂交等进行了研究。此类菌株的同核体菌株可通过与亲本对峙培养进行鉴定,但菌丝生长、菌落形态和吃料速度等与亲本没有显著差异,不同交配型的同核体之间交配时没有明显的交配现象。rpb2杂合位点标记可以用于鉴定该类型同核体菌株,且能验证是否交配。该类型同核体与之前发现的同核体类型之间可以进行杂交,杂交菌株可与两亲本都产生拮抗现象。该发现补充了之前建立的茯苓同核体鉴定方法,加深了对茯苓物种群体的了解,同时丰富了茯苓的育种资源。     

小菜蛾对多胺的嗅觉反应

在实验室条件下利用Y型嗅觉仪测试了小菜蛾Plutella xylostella成虫对多胺的嗅觉反应。结果表明：与蒸馏水对照比较,小菜蛾在交配前和交配后对精胺、亚精胺和腐胺这3种被测的多胺均有明显的趋性反应,但对3种多胺两两之间的选择则无显著差异;在对3种多胺和甘蓝Brassica oleracea叶汁之间的选择中,除未交配雄蛾对腐胺有明显的趋性（与甘蓝叶汁比较）和交配后雌蛾对甘蓝叶汁有明显的趋性（与精胺比较）外,其他均没有显著差异。表明多胺对小菜蛾具有引诱作用。     

Genetic investigation of the origination of allopolyploid with virtually synthesized lines: application to the C subgenome of Brassica napus

Although there are a number of different allopolyploids in the plant kingdom, the exact ancestral parents of some allopolyploids have not been well characterized. We propose a strategy in which virtual allopolyploid lines derived from different types of parental species are used to investigate the progenitors of an allopolyploid. The genotypes of the parental lines and the natural allopolyploid were established using a set of DNA molecular markers. The genotypes of the virtual lines were then derived from those of the parental lines, and compared extensively with that of the natural allopolyploid. We applied this strategy to investigate the progenitors of the C subgenome of Brassica napus (rapeseed, AACC). A total of 39 accessions from 10 wild and 7 cultivated types of the B. oleracea cytodeme (CC), and 4 accessions of B. rapa (AA) were used to construct 156 virtual rapeseed lines. Genetic structure was compared among natural rapeseed, virtual rapeseed lines, and their parental lines by principal component analysis and analysis of ancestry. Our data showed that the C subgenome of natural rapeseed was related closely to the genome of cultivated B. oleracea and its related wild types, such as B. incana, B. bourgeaui, B. montana, B. oleracea ssp. oleracea and B. cretica. This finding indicated that these types or their progeny might be ancestral donors of the C subgenome of rapeseed. The successful application of the strategy of virtual allopolyploidy in rapeseed demonstrates that it can possibly be used to identify the progenitors of an allopolyploid species.     

Utility of a multidisciplinary approach for genome diagnostics of cultivated and wild germplasm resources of medicinal Withania somnifera, and the status of new species, W. ashwagandha, in the cultivated taxon

Realizing the inconsistencies that exist in the extent and nature of differentiation in the Withania somnifera genetic resources in India, the 21 cultivated and wild accessions, and the two hybrids (cultivated?×?wild accessions and vice versa) were investigated for morphological, cytogenetical, chemical profiling, and crossability features. Their nuclear and chloroplast genomes were also assayed at the nucleotide sequence level, and by use of DNA markers. Chloroplast DNA diversity and somatic chromosome number (2n?=?48) were not helpful in identifying the differences. Other approaches, on the other hand, especially restriction endonuclease digests, types and sequence length composition of ITS 1 and ITS 2 of nuclear ribosomal DNA, AFLP fingerprinting, and crossability barriers unambiguously provided startling discrete differences between the cultivated and wild accessions, indicating a clear division of W. somnifera into two distinct lineages. These data, therefore, are indicative of the fact that because of the unique characteristics of its nuclear genome, and strong crossability barriers vis-à-vis wild accessions of W. somnifera, the cultivated accessions should be relegated to the rank of the separate species, W. ashwagandha.     

CHLOROPLAST DNA POLYMORPHISM SUGGESTS NIGERIAN CENTER OF DOMESTICATION FOR THE COWPEA,VIGNA UNGUICULATA (LEGUMINOSAE)

Twenty-one independent chloroplast DNA polymorphisms were identified in Vigna unguiculata defining 19 different chloroplast DNA molecules (plastome types). Two plastome types, differing by a single character, were found among 32 accessions of cultivated cowpea (Vigna unguiculata ssp. unguiculata). Eighteen different plastome types were found among 26 accessions of wild cowpea (V. unguiculata ssp. dekindtiana). The very low level of chloroplast DNA diversity found in cultivated accessions relative to wild cowpea suggests that 1) the domesticated form was derived from a narrow selection of the wild germplasm and 2) chloroplast gene flow between wild and cultivated types has been very limited. Cladistic analysis of the cpDNA data generated a robust tree completely lacking homoplasy. Three wild accessions from Nigeria possessed a plastome type indistinguishable from one present in cultivated accessions, suggesting that Nigeria represents one center of domestication of the cowpea. The other plastome type within the cultivated germplasm was not found among wild accessions.     

Chlororespiration is involved in the adaptation of Brassica plants to heat and high light intensity

Two species of Brassica were used to study their acclimation to heat and high illumination during the first stages of development. One, Brassica fruticulosa, is a wild species from south-east Spain and is adapted to both heat and high light intensity in its natural habitat, while the other, Brassica oleracea, is an agricultural species that is widely cultivated throughout the world. Growing Brassica plants under high irradiance and moderate heat was seen to affect the growth parameters and the functioning of the photosynthetic apparatus. The photosystem II (PSII) quantum yields and the capacity of photosynthetic electron transport, which were lower in B. fruticulosa than in B. oleracea, decreased in B. oleracea plants when grown under stress conditions, indicating inhibition of PSII. However, in B. fruticulosa, the values of these parameters were similar to the values of control plants. Photosystem I (PSI) activity was higher in B. fruticulosa than in B. oleracea, and in both species this activity increased in plants exposed to heat and high illumination. Immunoblot analysis of thylakoid membranes using specific antibodies raised against the NDH-K subunit of the thylakoidal NADH dehydrogenase complex (NADH DH) and against plastid terminal oxidase (PTOX) revealed a higher amount of both proteins in B. fruticulosa than in B. oleracea. In addition, PTOX activity in plastoquinone oxidation, and NADH DH activity in thylakoid membranes were higher in the wild species (B. fruticulosa) than in the agricultural species (B. oleracea). The results indicate that tolerance to high illumination and heat of the photosynthetic activity was higher in the wild species than in the agricultural species, suggesting that plant adaptation to these stresses in natural conditions favours subsequent acclimation, and that the chlororespiration process is involved in adaptation to heat and high illumination in Brassica.     

转拟南芥P5CS1基因增强羽衣甘蓝的耐旱性

为提高羽衣甘蓝的耐旱性,本文将拟南芥Δ1-吡咯啉-5-羧酸合成酶（P5CS1）基因经农杆菌介导转入羽衣甘蓝植株中,检测转基因株系与野生型植株在干旱胁迫下P5CS1 mRNA表达量、幼苗脯氨酸含量、株系根系性状、整株干重、鲜重和整株存活率。结果表明,在15%PEG6000渗透胁迫下,转基因植株的P5CS1基因mRNA表达量明显增加,转基因植株脯氨酸含量是野生型的2.4倍;主根长、最长侧根长、侧根数目、整株干重和鲜重均高于野生型,干重/鲜重则低于野生型,转基因植株的平均存活率为78%,极显著高于野生型。数据显示,AtP5CS1基因在羽衣甘蓝中的表达明显改善了转基因植株的耐旱性。     

The intergradation, genetic interchangeability and interpretation of gene conversion spectrum types

In the Pasadena strains of Ascobolus immersus, the gene conversion propperties of 29 induced (nine UV, nine NG, and 11 ICR-170) and nine spontaneous white-ascospore mutations have been studied. Each mutant was crossed to three types of derived wild-type strains; single mutants often gave very different conversion results in the three types of crosses, with any or all of the following changes in: percentage with post-meiotic segregation among aberrant-ratio asci; percentage with conversion to wild type among aberrant-ratio asci; and in total conversion frequency. - These results are compared with those of Leblon (1972 a, b) from Ascobolus immersus and Yu-Sun, Wickramaratne and Whitehouse (1977) from Sordaria brevicollis. It is shown that conversion spectrum types are not necessarily distinct, but can completely intergrade, on the criteria of both post-meiotic segregation frequency and direction of correction. Genetic differences between strains in the present work resulted in much interchangeability of spectrum types for the same mutation in different crosses; e.g., from type C in one cross to type B/D type in another cross, although the mutation is presumably of the same molecular type (addition or deletion frame shift, or base substitution) in each cross. These changes of conversion properties for a given mutation in different crosses mean that previous interpretations of spectrum types in terms of specific conversion properties for various molecular types of mutation are inapplicable, or inadequate on their own, to explain the present data. Other factors, such as heterozygous cryptic mutations or conversion control genes, are probably involved. Because of asymmetric hybrid DNA formation, correction properties may differ from observed conversion properties.     

Evolution of Polaskia chichipe (Cactaceae) under domestication in the Tehuacan Valley, central Mexico: reproductive biology

Polaskia chichipe, a columnar cactus, is cultivated for its edible fruits in central Mexico. This study analyzed whether artificial selection has modified its reproduction patterns and caused barriers to pollen exchange between wild, managed in situ, and cultivated populations. Anthesis was diurnal (～16 h in winter, ～10 h in spring) as well as partly nocturnal (～12 h in winter, ～3 h in spring), and flowers were pollinated by bees, hummingbirds, and hawk moths. Manual cross-pollination was ～37-49% effective in all populations. Self-pollination was ～12% successful in the wild, but twice as successful (～22-27%) in managed and cultivated populations. Diurnal pollination was ～35-55% effective in winter and 100% in spring. Nocturnal pollination was successful only in winter (15%). Crosses among individuals were more effective within populations than among populations, including populations under a similar management regimen. The least successful crosses were between wild and cultivated populations. Flowers were produced in all populations from January to March, but flowering peaks differed by 1 mo among wild, managed, and cultivated populations and by 2 mo between wild and cultivated populations. The latter interrupted pollen exchange in May. Seeds from managed and cultivated populations germinated faster than those from wild individuals. Domestication has seemingly favored self-compatible P. chichipe plants with higher fruit yield, a longer period of fruit production, and faster seed germination, attributes that have resulted in partial reproductive barriers between wild and manipulated populations.     

Crossability analysis in subgenus Tulipa of the genus Tulipa L.

A range of almost 1400 cross combinations has been carried out between 31 species of Tulipa subgenus Tulipa. Most of the sections are well separated reproductively from each other. The designated species aggregates in section Clusianae appeared to be intersterile. Also in section Kolpakowskianae the species, as far as used, cannot be combined. Some crosses between species of section Tulipanum succeeded. The species of sections Eichleres and Tulipa (including the cultivated tulip T gesneriana ) could be combined in various ways, although the highest level of seed set was achieved within either section. The crossability data support the current taxonomic division. The level of reproductive isolation between sympatric species is discussed, and the importance of crossability studies for plant breeding in Tulipa pointed out briefly.     

Spontaneous gene flow from rapeseed (Brassica napus) to wild Brassica oleracea

Research on the environmental risks of gene flow from genetically modified (GM) crops to wild relatives has traditionally emphasized recipients yielding most hybrids. For GM rapeseed (Brassica napus), interest has centred on the 'frequently hybridizing' Brassica rapa over relatives such as Brassica oleracea, where spontaneous hybrids are unreported in the wild. In two sites, where rapeseed and wild B. oleracea grow together, we used flow cytometry and crop-specific microsatellite markers to identify one triploid F1 hybrid, together with nine diploid and two near triploid introgressants. Given the newly discovered capacity for spontaneous introgression into B. oleracea, we then surveyed associated flora and fauna to evaluate the capacity of both recipients to harm cohabitant species with acknowledged conservational importance. Only B. oleracea occupies rich communities containing species afforded legislative protection; these include one rare micromoth species that feeds on B. oleracea and warrants further assessment. We conclude that increased attention should now focus on B. oleracea and similar species that yield few crop-hybrids, but possess scope to affect rare or endangered associates.     

Chloroplast and nuclear DNA studies in a few members of the <Emphasis Type="Italic">Brassica oleracea</Emphasis> L. group using PCR-RFLP and ISSR-PCR markers: a population genetic analysis

A population genetic analysis of chloroplast and nuclear DNA was performed covering nine wild populations of Brassica oleracea. Three members of the n = 9 group, all close to B. oleracea, Brassica alboglabra Bailey, Brassica bourgeaui (Webb) O. Kuntze and Brassica montana Pourret, were also studied to better understand their relationship with B. oleracea. Chloroplast DNA was analysed using the PCR-RFLP (polymerase chain reaction - restriction fragment length polymorphism) method. The ISSR-PCR (inter-simple sequence repeat - polymerase chain reaction) technique was adopted to study nuclear DNA. Twelve primer pairs of chloroplast DNA showed very good amplification. The amplified product of each primer pair, digested by three restriction enzymes, revealed no variation of cpDNA among the taxa studied. This indicates they may have the same chloroplast genotype. Seven selected ISSR primers have detected genetic variation, both within and among the populations/taxa surveyed. The information obtained on the intra- and inter-populational genetic diversity of wild populations of B. oleracea neatly defined the individual plants. It could provide important guidelines for backing management and conservation strategies in this species. The study confirms a close relationship between B. alboglabra, B. bourgeaui and B. montana, which is parallel to their morphological similitude.