Influence of environmental factors on a population of goitred gazelles (Gazella subgutturosa subgutturosaGüldenstaedt, 1780) in semi-wild conditions in an arid environment: a preliminary study

A population of goitred gazelles (Gazella subgutturosa subgutturosaGüldenstaedt, 1780) has been created and maintained in the Bukhara Breeding Centre, Uzbekistan since 1977. Population dynamics and range usage have been analysed for the period from 1978 to 1995. In 1989 the population in 5126 ha of the reserve peaked at 1224; in 1995 it was 580. Breeding success was correlated with meteorological conditions and was density-dependent. Changes of plant associations, connected with the gazelles population growth, are discussed.     

Analysis of survival curves in seasonally mated pastoral goat herds in northern Kenya using logistic regression techniques

In order to assess the effect of controlled seasonal breeding on survival performance of pastoral goat flocks, a systematic breeding programme was initiated in a herd of small East African goats over a period of 4 years in Isiolo District, northern Kenya. This papers presents an analysis of survival rates observed in six different mating seasons. The statistical analysis is based on modelling hazard functions parametrically over time using logistic regression and polynomial spline functions. With respect to kid survival, litter size and parity of dam failed to reach statistical significance after adjustment was made for the effects of birth weight and milk yield until weaning. Highly significant interactions were found between time factors and the effect of mating season, indicating non-proportionality of death risks across mating seasons. Confining mating to the period between June and November is likely to confer a distinctive advantage in terms of young livestock survival. In contrast, joining does during the short dry season leads to kid mortality rates of about 50%, and should therefore be avoided. Doe survival was evaluated in terms of mating season, production cycle, parity, and reproductive status. The ranking of mating season groups with respect to doe survival was similar to that observed in kids, although the differences were much smaller and non-significant. The lowest annual mortality rate was observed when breeding females were mated during the long dry season. It is concluded that confining breeding to the long dry season can be an effective management intervention to reduce mortality rates in pastoral goat flocks.     

The Ecology of Intertidal Amphipods in the Oslofjord. The Life Cycles of Chaetogammarus marinus and C. stoerensis

Abstract. In the Oslofjord two species of the amphipod genus Chaetogammarus, C. marinus (LEACH, 1815) and C. stoerensis (REID, 1938) were found to be annual species with similar life cycles. No differences in life cycle traits were found between two C. stoerensis populations where one occupied a freshwater influenced beach and the other a fully marine beach. The breeding period of both species was short and lasted from April to the end of May or early June. Frost prohibited embryonic development in the first part of April so few juveniles were released before the middle of May. In late May and early June all specimens which survived the winter died. The sex ratio was skewed in favour of females, and females produce two to three broods during lifetime. Between 16 and 31 % of the newly laid eggs failed to complete their development. The life cycle of populations of the two species from other geographical areas are compared with the Oslofjord data.     

滦河口湿地黑嘴鸥原繁殖地恢复研究

滦河口湿地曾是世界四大黑嘴鸥繁殖地之一。近年来该地生态环境日益恶化,使黑嘴鸥失去了繁殖地。该文分析滦河口湿地环境因子变化和人为干扰对黑嘴鸥繁殖的影响,探讨恢复黑嘴鸥原繁殖地生态环境的目标和关键问题,为滦河口湿地恢复黑嘴鸥繁殖地以及有效保护黑嘴鸥种群提供理论依据。     

两种鹤虱属短命植物的繁育系统及其对荒漠环境的适应

两形果鹤虱（^{Lappula duplicicarpa}）和异形狭果鹤虱（^{L. semiglabra}）是两种广泛分布于新疆准噶尔荒漠的具异形果实的早春短命植物。两种植物同一花中均能产生两种形态、脱落及扩散方式明显不同的小坚果,且同一花序上不同部位的花中产生的异形果实比例不同。重点对两种植物的繁育系统与异形果实的产生是否存在联系,以及它们与准噶尔荒漠环境相适应的特点进行了观察。结果表明：①二者花均为两性,植株上同一花中以及花序上产生不同比例异形果实的花之间在花各部的数目与形态、单花花粉量(P)、胚珠数(O)和P/O值上表现均很稳定,与异形果实的产生没有直接联系。②单花花期一般在24 h左右,开花时间不受气候因素的影响。③两种植物的花粉育性均很高,花粉可育率分别为(91.0±4.7)％和(93.2±4.3)％。④散粉时二者的花粉活力均不高,散粉后花粉活力的动态变化基本一致,最佳授粉期分别在2 h和3 h以内,柱头的最佳可授期均在3 h以内,花粉的最佳授粉期与柱头的最佳可授期高度吻合。⑤ 两种植物的P/O值分别为1 222±197和3 419±426,属于混合式繁育系统,这与套袋实验及自花授粉的荧光显微观察结果相一致。⑥ 两种植物在繁育系统上所表现出的特点,避免了准噶尔荒漠的多风、温湿度变化大等恶劣环境条件对其开花、传粉过程的不利影响,保障了繁殖成功。这些结果将为探讨短命植物对准噶尔荒漠的生态适应机制提供重要的理论依据。     

新质源抗稻瘟病籼型不育系湛A的选育研究

以东莞野生稻为细胞质供体,梅青B×II-32B的后代为细胞核供体,经杂交和连续多代回交核置换,转育成新质源三系不育系湛A。选育结果:湛A育性稳定,不育株率100%,花粉不育度99.95%,典败花粉率95.64%,异交结实率高,抗稻瘟病,中抗白叶枯病,恢复谱较广,配合力好。     

干旱荒漠地区沙地樟子松育苗试验研究

春季低温低湿、大风频繁,夏季干旱高温,土壤颗粒粗,持水力低是干旱荒漠地区沙地樟子松育苗的主要制约性因素。只要抓好土壤改良、春季苗床覆盖、灌水、遮荫、越冬覆盖和施肥施药等措施,即可保证沙地樟子松育苗的成功。     

延津沙地草食畜饲养管理技术及发展模式探索

在对延津沙区引入的鲁西高腿有角小尾寒羊的饲养、管理和繁育技术试验基础上,探讨了集约化的养殖模式、发展模式和经营模式,并进行了乔灌草三结合的饲草料基地建设和粮经饲三元种植结构的尝试及饲草料加工的技术示范,为豫北沙区发展小尾寒羊的规模养殖和肉羊生产开辟了新的途径。     

北太平洋柔鱼生殖群体结构特征及繁殖生物学

根据2010年6～9月北太平洋柔鱼(Ommastrephe bartramii)渔业的现场调查资料,分析了北太平洋柔鱼胴长和体质量组成结构、性比、初次性成熟胴长、群体成熟度指数等等基础性的渔业生物学参数,阐述了该海域柔鱼的种群结构动态及繁殖生物学的特征。结果表明:各月北太平洋柔鱼生殖群体中雌性个体数量大于雄性,且雌性个体的平均胴长及体质量均显著大于雄性;生殖群体中雌、雄个体胴长与体质量关系的差异极为显著;相同胴长组下雄性个体的性成熟率要高于雌性;北太平洋柔鱼初次性成熟胴长ML50%♀为261.83 mm;ML50%♂为255.60 mm,雄性初次性成熟胴长显著小于雌性;东部海区(170°W～178°W)生殖群体比例及个体大小明显高于西部海区传统作业渔场(150°E～160°E)。判断东西部海区柔鱼是否是同一群体,还需要连续性的调查,进一步分析其成熟度随时间的变化及利用耳石信息分析技术来确定,还可以用微卫星技术测定分析以及标志放流法来判定,结论更为准确。     

High genetic diversity in gametophyte clones of Undaria pinnatifida from Vladivostok, Dalian and Qingdao revealed using microsatellite analysis

Breeding practice for Undaria pinnatifida (Harvey) Suringar requires the screening of a large number of offspring from gametophyte crossings to obtain an elite variety for large-scale cultivation. To better understand the genetic relationships of different gametophyte cultures isolated from different sources, 20 microsatellite loci were screened and 53 gametophyte clone cultures analyzed for U. pinnatifida isolated from wild sporophytes in Vladivostok, Russia and from cultivated sporophytes from Dalian and Qingdao, China. One locus was abandoned because of poor amplification. At the sex-linked locus of Up-AC-2A8, 3 alleles were detected in 25 female gametophyte clones, with sizes ranging from 307 to 316 bp. At other loci, 3 to 7 alleles were detected with an average of 4.5 alleles per locus. The average number of alleles at each locus was 1.3 and 3.7 for Russian and Chinese gametophyte clones, respectively. The average gene diversity for Russian, Chinese, and for the combined total of gametophyte clones was 0.1, 0.4, and 0.5, respectively. Russian gametophyte clones had unique alleles at 7 out of the 19 loci. In cluster analysis, Russian and Chinese gametophyte clones were separated into two different groups according to genetic distance. Overall, high genetic diversity was detected in gametophyte clones isolated from the two countries. These gametophyte cultures were believed to be appropriate parental materials for conducting breeding programs in the future.