陕西及甘,宁部分地区豆科植物根瘤菌资源调查

通过对陕西全省及甘、宁部分地区豆科植物瘤菌资源进行调查,共采集到４４属１０９种豆科植物根瘤３８７份,其中蝶形花亚科中有９４．６％的植株能结瘤固氮,槐属和香槐属中的一些种及云实亚科中的云实和紫荆未见结瘤。对部分菌株的固氮酶活性进行了测定,自然瘤的固氮酶活性比回接瘤的固氮酶活性低。     

提取TTX后鲀鱼废物的氨基酸分析

我国鲀鱼类资源丰富,鲀鱼肝脏、卵巢提取ＴＴＸ后的废物中,含有１７种氨基酸,其含量合计占干物质的７１．５％,其中人和动物必需的８种氨基酸中Ｔｈｒ、Ｖａｌ、Ｉｌｅ、Ｌｅｕ、Ｐｈｅ和Ｌｙｓ６种含量较高,总量占干物质的２７．６％以上。     

Competition and the compensatory regulation of fruit and seed set in the perennial herb Epilobium dodonaei (Onagraceae)

I studied the effects of competition and soil fertilization on variation of seed yield components of the outcrossing perennial Epilobium dodonaei Vill. using a randomized complete block design. Fertilization as a main effect was not significant. Competition, however, reduced the number of flower buds per shoot (-29%), the number of ovules per fruit (-12%), and the number of ripe fruits per shoot (-51%). In addition, competition caused an increase in abortion of flower buds. Consequently the fruit/flower bud ratio decreased from 0.71 to 0.47. Average seed mass was not reduced significantly by competition. Some of the negative effects of competition on fruit production were mitigated by fertilization. However, competition considerably reduced the proportion of late-aborted seeds, which resulted in an increase of the seed/ovule ratio from 0.31 to 0.49 (+58%). As a consequence of this compensation, the reduction in the number of seeds per shoot due to competition was not significant. At the level of the genet, competition had a strong effect on seed yield due to decreases in the number of shoots produced. I discuss patterns of regulation at consecutive levels of reproduction. Shoots of plants suffering from competition initially invested less in reproductive structures than the control and showed a higher abortion rate of less costly structures early in reproductive development, but also had a lower abortion rate later in their development. The observed compensatory pattern in yield components illustrates the fine-tuning regulation capacity at different levels of reproductive development in plants.     

Morphological and molecular variation among populations of octoploid Fragaria virginiana and F. chiloensis (Rosaceae) from North America

Relationships among 37 North American octoploid strawberry populations were studied by evaluating 44 morphological traits and 36 randomly amplified polymorphic DNA (RAPD) markers. Both data sets were analyzed by principal components analysis and UPGMA clustering based on genetic distances. Morphological data defined five groups: east of the Missouri River (Fragaria virginiana ssp. virginiana), the Black Hills (F. virginiana ssp. virginiana and ssp. glauca), from the eastern Cascades to the eastern Rocky Mountains (F. virginiana ssp. glauca), the western Cascades and Olympic Peninsula (F. virginiana ssp. platypetala), and the Pacific coast (F. chiloensis). Canonical discriminant analysis clearly discriminated populations into these provenances, suggesting that these groups are morphologically distinct. RAPD data defined three groups, one with F. virginiana ssp. virginiana and ssp. glauca, another with F. chiloensis, and a third with F. virginiana ssp. platypetala. The latter was more similar to F. chiloensis than F. virginiana, suggesting it is likely a subspecies of F. chiloensis. All octoploid North American strawberries have likely derived from a common ancestor and have differentiated into F. chiloensis and F. virginiana by adapting to moister and drier environments, respectively.     

FLORAL SEX ALLOCATION IN SEQUENTIALLY BLOOMING PLANTS

In plants whose flowers develop in a sequence, different flowers may exhibit temporal variation in pollen donation and receipt such that the fitness contributions through male and female functions can vary among flowers. Dichogamy, or directional pollinator movements within inflorescences, can create situations where flowers in different stages in the sequence may differ in the numbers of flowers in the female stage available as potential mates. We present an evolutionarily stable strategy (ESS) analysis of the resource allocations expected in different flowers in hermaphroditic plants when the mating environments vary among flowers. This introduces a modular element into sex-allocation models. Our analysis shows that such variation in the mating environments of flowers can select for differences in sex allocation between flowers. When male and female fertilities are nonlinear functions of the allocations, variation in resource availability can also select for variation in sex allocation among flowers. The influence of dichogamy and pollinator directionality on floral sex allocation is discussed, and the empirical evidence supporting the predictions derived from the model is briefly reviewed. The implications of our results for the evolution of andromonoecy and monoecy are discussed.     

甘肃省动植物资源现状及可持续发展对策

甘肃地处中国的中部偏北，位于黄土高原、内蒙古高原和 藏高原的交汇处，是我另唯一横跨三大自然区的 分。全省的动植物资源极春丰富。据不完全调查，共有脊椎动物９２４种和亚种，占国内４８６５种１９．０１％，种子植物３８６７种，占国内３００００种的１２．９％。由于生态环境破坏，乱捕滥猎，使动植物相断消失，许多国家级保护的动植物成为濒危物种。为保护生态环境，实现可持续发展，本文提出了５项持续利用的对策：１）加     

Geographical variation in AdhF and alcoholic resource utilization in Indian populations of Drosophila melanogaster

Indian geographical populations of Drosophila melanogaster, collected at latitude 10–32.3 ^oN, longitude 76.1–80.1 ^oE and altitude 16–2050 m, were analysed for changes in Adh ¹ frequency and utilization potential of diverse alcoholic resources. Until now, there have been limited data on climatic association of correlated changes on these aspects in continental populations of D. melanogaster. Indian populations demonstrate an increase in Adh ^F frequency by 0.04 per degree latitude and significantly higher utilization of ethanol (9.0–15.2%), acetic acid (8.1–12.5%), n-propanol (2.55-4.25%), 2-propanol (1.5-3.5%), n-butanol (2.15 3.5%) and 2-butanol (0.68-1.2%). Data also revealed significant correlation with latitude as well as altitude. Regression analysis of climatic data from collection sites confirmed the observed clinal variation of Adh ^F as well as alcoholic utilization in D. melanogaster. On the Indian subcontinent, variation in Adh ^F frequency and alcoholic resource utilization along increasing latitude as well as altitude are due to climatic selection factors such as temperature and rainfall.     

河西走廊的麻黄资源及其保护

河西走廊的麻黄资源及其保护满多清,杨自辉（甘肃省治沙研究所,武威７３３０００）关键词麻黄;植物资源;保护ＴｈｅｒｅｓｏｕｒｃｅｓｏｆＥｐｈｅｄｒａＴｏｕｒｎ．ｅｘＬ．ａｎｄｔｈｅｉｒｃｏｎｓｅｒｖａｔｉｏｎｉｎＨｅｘｉｃｏｒｒｉｄｏｒ￥ＭａｎＤｕｏ－...     

Patterns of lake acidity and waterfowl communities

Breeding waterfowl communities were studied in 28 lakes in three areas in North Europe, along gradients of acid precipitation and alkalinity that result in lake conditions ranging from unaffected to strongly acidified. Acidic lakes had generally sparser and less complex vegetation, and fewer invertebrates were caught in activity traps. There was neither correlation between pH and waterfowl species richness (genus Anas, family Anatidae, and waterfowl sensu latu tested separately), nor between pH and waterfowl diversity (Simpson's index). Further, pH and waterfowl population density (genus Anas, family Anatidae, and waterfowl sensu latu) were not correlated, but when functional rather than taxonomic groups were considered, pH and relative abundance of fish-eating species (Gaviidae and Podicipedidae) were correlated. However, the relative abundance of Bucephala clangula, a diving duck that may compete with fish for food, was not correlated with pH. Although individual species may be affected, community level responses of waterfowl to acidity are either absent or hard to detect at our sites.