不同倍性麦类作物HI和NHI的杂种优势及其与产量的关系

本研究利用冬性和春性四倍体硬粒小麦(Triticum durum,AABB)、普通小麦(T.aestivum,AABBDD),春性和冬性六倍体小黑麦(AABBRR)及春性八倍体小黑麦(AABBD-DRR)等三种倍性六套材料,分别在每套材料中选取亲本并配成双列杂交以研究倍性与杂种优势的关系。结果表明:①冬性倍性材料间一致地表现出单株经济产量具有最高的杂种优势,单株经济产量优势高的主要原因在于生物产量的优势较高,收获指数一般优势较小。②不同倍性间亲本产量水平与杂种优势幅度表现出不同关系。冬性硬粒小麦产量水平与杂种优势幅度呈显著正相关,而普通小麦和八倍体小黑麦这种相关不显著。③倍性间杂种优势的比较表明普通小麦产量杂种优势略高于硬粒小麦,超亲优势无差异,表明在 AABB 内增加 D 染色体组似乎不会影响杂种优势的幅度。但小黑麦杂种优势和超亲优势明显低于硬粒小麦和普通小麦,似乎在 AABB 或 AABBDD 中增加 R 染色体组降低了杂种优势的幅度。     

稻瘟菌株CH63和TH16杂交后代毒性变异及其无毒基因组成

 报道了两个稻瘟菌株CH63和TH16的杂交后代在36个水稻品种上的致病性分离、遗传分析以及无毒基因组成的分析结果。78个子囊孢子菌株中呈现显著的致病性分离，共出现71种致病类型，在不同品种上分别出现1∶1、1∶3、3∶1、1∶7、1∶15和15∶1等的无毒性/毒性分离，表明供试菌株对不同品种的无毒性/毒性是一个或多个基因控制的。遗传学分析结果表明，亲本菌株对不同品种的无毒性/毒性控制存在多种类型。菌株CH63对品种K 59(Pi-t)、中98－18、特特普、T 641、C 102 TTP(Pi-4)、C 101 TTP 6、E No.11、农虎6号、C 101 PKT(Pi-4a)、C 105 TTP-1(Pi-4)、中156 和中98－19分别持有1个无毒基因；对品种1461选、6392选、麻谷泰引1号、Lemont、宫崎7号、Vandana、长香稻、青珍8号和珍优3号分别持有2个无毒基因；对于品种草笛（Pi-k）、品种20中－1 、C 104 LAC(Pi-1)、C 103 TTP(Pi-1+1b)、K 3(Pi-kh)、梅雨明 (Pi-km)和东农363分别持有2个以上无毒基因；亲本菌株对于品种四丰43、珍龙13、C101LAC和20中－2分别持有2个无毒基因，关东51、欧244持有2个以上的无毒基因，但因亲本菌株对品种的致病型一致，难以判断控制菌株对品种非亲和性的基因来源。     

杏杂合位点共显性标记的分离方式及连锁图谱构建

以‘串枝红’ב金太阳’杏的F1代为材料,在分析共显性标记分离方式的基础上利用简单重复序列（SSR）和相关序列扩增多态性（SRAP）标记,构建了两张杏分子连锁图谱。‘串枝红’图谱共14个连锁群,包含37个SSR标记和32个SRAP标记,连锁群总长度为1086.6cM,每连锁群平均长度77.6cM,标记间平均连锁距离为1...     

Environmental correlates of two macro-decapods distribution in Central Italy: Multi-dimensional ecological knowledge as a tool for conservation of endangered species

Using a multi-dimensional ecological design, this study aimed first to analyse whether local environmental conditions can account for the spatial segregation of two Italian native decapods, the crayfish Austropotamobius italicus and the river crab Potamon fluviatile, in Central Italy freshwater ecosystems. Second, we aimed to analyse which environmental variables were more closely associated with the presence/absence of the two decapods in specific sites within their distribution area. Following a factorial design, a total of 32 sites were selected in two neighbouring geographic areas, one occupied by crayfish and one by crabs. Within each distribution area, eight streams where the decapod was present and eight where it was not present were selected. At each site, macro-invertebrate community composition and 16 abiotic variables were recorded and analysed with multi-variate methods. Variations in physical (minimum and maximum temperatures), chemical (calcium, oxygen, nitrate and nitrite) and geomorphological (substrate composition) parameters explained spatial segregation of P. fluviatile and A. italicus in the study area. The occurrence of crayfish reflected variations of chemistry (such as pH, calcium, nitrate and nitrite concentrations), temperature, water depth and substrate composition. On the contrary, the presence of the river crab, within its occurrence zone, was not associated to any biotic and abiotic parameters and was probably affected by anthropogenic pressure and uncontrolled harvesting. These findings provide fundamental ecological data for the maintenance of the two decapod natural populations as well as for the selection of areas and streams adequate for their reintroduction.     

Sex differences in population genetics, home range size and habitat use of the parti-colored bat (Vespertilio murinus, Linnaeus 1758) in Switzerland and their consequences for conservation

When habitats are declining, niche segregation by demographic groups, such as the two sexes, can have a profound impact on the extinction risk of a species as a whole. Thus, differences in the requirements of demographic groups are of importance in conservation. We combined behavioural and genetic data to investigate whether the sexually segregated parti-colored bat (Vespertilio murinus) exhibits sex-specific niche partitioning. We use our data to evaluate implications for conservation of this potentially vulnerable species in Switzerland, the western boundary of its range. Using radio-telemetry, we found sex-specific differences in habitat use. Foraging females strongly relied on lakes while foraging males displayed more flexibility in their habitat use. Moreover, males covered significantly larger foraging areas than females. Sequencing 341 base pairs of the mitochondrial D-loop of 247 individuals revealed sex-specific differences in the genetic structure of colonies, but no such difference was observed for three nuclear micro-satellite markers. We found high mtDNA diversity in two Swiss male colonies and one German female colony, but low mtDNA diversity in two Swiss female colonies. Our genetic data suggest that considerable gene flow occurs via male dispersal and mating. At the same time immigration of females into the existing female colonies in Switzerland is rare compared to the immigration of new males into male colonies. Since we found the sexes in Vespertilio murinus to differ markedly in their ecology, population genetics, and behaviour, we conclude that sex-specific conservation plans are required to protect this species efficiently.     

Depth-specific distribution and importance of nitrite-dependent anaerobic ammonium and methane-oxidising bacteria in an urban wetland

Anaerobic ammonium oxidation (anammox) and nitrite-dependent anaerobic methane oxidation (n-damo) are two recently discovered processes in the nitrogen cycle that are catalysed by anammox bacteria and n-damo bacteria, respectively. Here, the depth-specific distribution and importance of anammox bacteria and n-damo bacteria were studied in an urban wetland, Xixi Wetland, Zhejiang Province (China). Anammox bacteria related to Candidatus Brocadia, Candidatus Kuenenia and Candidatus Anammoxoglobus, and n-damo bacteria related to “Candidatus Methylomirabilis oxyfera” were present in the collected soil samples. The abundance of anammox bacteria (2.6–8.6 × 10⁶ copies g⁻¹ dry soil) in the shallow soils (0–10 cm and 20–30 cm) was higher than that (2.5–9.8 × 10⁵ copies g⁻¹ dry soil) in the deep soils, whereas the abundance of n-damo bacteria (0.6–1.3 × 10⁷ copies g⁻¹ dry soil) in the deep soils (50–60 cm and 90–100 cm) was higher than that (3.4–4.5 × 10⁶ copies g⁻¹ dry soil) in the shallow soils. Anammox activity was detected at all depths, and higher potential rates (12.1–21.4 nmol N₂ g⁻¹ dry soil d⁻¹) were observed at depths of 0–10 cm and 20–30 cm compared with the rates (3.5–8.7 nmol N₂ g⁻¹ dry soil d⁻¹) measured at depths of 50–60 and 90–100 cm. In contrast, n-damo was mainly occurred at depths of 50–60 cm and 90–100 cm with potential rates of 0.7–5.0 nmol CO₂ g⁻¹ dry soil d⁻¹. This study suggested the niche segregation of the anammox bacteria and n-damo bacteria in wetland soils, with anammox bacteria being active primarily in deep soils and n-damo bacteria being active primarily in shallow soils.     

甘蓝型油菜单倍体植株群体的构建

以油菜双低（低芥酸、低硫苷）品种＂沪油12＂的小孢子来源植株为试验材料,研究了供体植株不同外植体部位不定芽再生情况及影响不定芽诱导的一些因素,并对甘蓝型油菜小孢子来源的再生组培苗进行了染色体倍性的鉴定.结果表明,利用节间茎段进行不定芽诱导是一种较好的快速再生植株方式,具有出芽快,遗传特性保持好的特点.茎段具有较强的不定芽分化能力,而叶柄和叶片难以诱导分化出芽.通过优化培养基,建立了甘蓝型油菜小孢子来源植株茎段高频不定芽再生系统.通过对甘蓝型油菜组培苗的叶片气孔保卫细胞和根尖染色体数目的观察,确定了一批小孢子来源的单倍体植株.     

Meiosis and fertility in interspecific hybrids of Nicotiana tabacum L. ×N. glauca Grah. and their derivatives

Nicotiana glauca is of potential interest to breeders as it carries resistance to black root rot of tobacco. Cytological investigations of sexual interspecific hybrids of N. tabacum T′T′TT (2n = 4x = 48) cv. ‘Wiślica’ × N. glauca GG (2n = 2x = 24) were carried out. The analyses of chromosome association at diakinesis and metaphase I in the PMCs of amphihaploid F₁ T′TG (2n = 3x = 36) revealed low variable pairing with 0–5 bivalents. The sterile amphihaploids F₁ were converted into partial female fertile amphidiploids T′T′TTGG by chromosome doubling. Among 36 mature plants obtained, 15 were found to have chromosome numbers (2n = 6x = 72) and were verified as amphidiploids, 9 had (2n = 6x = 70 or 71) chromosomes while the remaining 12 were haploid. True amphidiploids, in spite of quite high chromosome pairing during meiosis, were very different in pollen fertility, ranging from 0% to 85%. Male fertility disturbances did not correlate with the degree of female fertility upon pollination with N. tabacum. Sesquidiploids T′TG (2n = 5x = 60) obtained from backcrossing the amphidiploids to parental tobacco showed more than 22 bivalents, 10–12 univalents and occasional multivalents that indicated the possibility of interchange events between N. tabacum and N. glauca genomes.     

Dihaploid Plant Production from 4 × -Genotypes of Potato by the Use of Efficient Anther Plants Producing Tetraploid Strains (4 × EAPP-Clones) — Proposal of a Breeding Methodology

Tetraploid clones of potato with a superior efficiency in producing androgenetic plants (4 × EAPP-clones) have been obtained by culturing in vitro anthers of 2 × EAPP-clones. The latter were isolated by three cycles of recurrent selection from diploid breeding material (UHRIG 1985 a). In this paper we report on the capacity of 4 × EAPP-clones, when crossed to in vitro unresponsive 4 × genotypes, to transmit to their F₁ their androgenetic potential, Five 4 ×× 4 × F₁ crosses were considered, which produced on average 35 embryoids per flower – a value higher than that of nonresponsive 4 × genotypes (no embryoids obtained), but-also significantly better than the value found for 4× EAPP-clones (9.8 embryoids per flower). The hybrid families behaved differently from each other, with one producing up to 63 embryoids per flower. A range of per plant values was, moreover, found, revealing the existence of a large variability among sister plants belonging to the same F₁ cross. The presented data indicate a rather simple inheritance of dominant genetic factors acting in favor ot androgenesis. They also suggest that the utilized 4× EAPP-clones were possibly heterozygous for such genes. Data are also reported on the ploidy level of anther plants obtained from 4× and 2× EAPP-clones. In this respect 2× EAPP-clones show the interesting capacity of generating, via anther culture, a consistent fraction of tetraploid plants (13,7 %). Based on the findings reported in this paper we propose, for tetraploid S. tuherosum L., a cyclic breeding procedure making use of anther culture and where ploidy level alternates, within a cycle, between 2× and 4×.     

华农本地早×宜昌橙杂交后代几个性状的遗传分离研究

对华农本地早×宜昌橙的Ｆ１、Ｆ２代杂种，在５个性状上的分离、重组进行了观察分析。结果表明，多胚性受显性基因控制，华农本地早与宜昌橙分别处于显性杂合和隐性纯合状态；种子子叶颜色受一个主基因控制，白色子叶时绿色子叶为显性；嫩梢颜色的遗传基础较为复杂，绿色嫩梢对紫色嫩梢有显性作用；翼叶大小与树体抗寒能力为受多基因控制的数量性状。