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Abstract The smooth marron, Cherax cainii Austin, now occurs in regions of Western Australia that are warmer and drier than those of the natural distribution. Animals sourced along a south to north geographical axis decrease in body mass per unit length. Juveniles reared from gravid females sourced from four sites along this axis were raised in common laboratory conditions for 14 weeks. No differences between sites were observed in body mass, standardised for length, indicating that in situ differences are a phenotypic response to local conditions. 相似文献
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Jin-Won LEE 《中国鸟类》2012,3(4):312-319
了解一个物种种群内多态性的发生及其进化,是进化生物学的挑战之一。鸟类卵色的多态性是其中一个重要例子,分裂选择被认为是鸟类卵色多态性进化的机制。我们对韩国境内的棕头鸦雀(Paradoxornis webbianus)种群的卵色变化进行了调查,采用光纤光谱仪来确定纯蓝和纯白卵色的出现比率。结果表明,不同地理种群的鸦雀的蓝、白卵色的比率不同,高纬度地区蓝色卵的比例较少,而随着纬度南移,蓝色卵的比例逐渐增多。种群之间的卵色比率变化模式与种群内卵色的比率变化不同。本文探讨了棕头鸦雀卵色多态性进化的理论假设。 相似文献
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Dolores Uribe-Salas Cuauhtémoc Sáenz-Romero Antonio González-Rodríguez Oswaldo Téllez-Valdéz Ken Oyama 《Forest Ecology and Management》2008
Quercus rugosa Nee (section Quercus) has a distribution from the southern United States to Honduras. This study characterized leaf variation across the whole distribution of the species in Mexico. Ten foliar morphometric characters were scored in each of 241 individuals from 25 localities. A principal component analysis resolved four principal components (PCs) that explained 76.4% of the total variation. A nested analysis of variance revealed significant differences among populations (29.2% average contribution to total variance for the four PCs) and among-trees within populations (39.2%), while 31.6% was due to intra-individual variation. For the first PC (related to leaf size), 52.1% resulted from among population differences. This variation was negatively correlated with latitude (r = −0.86; P < 0.0001), indicating a steep clinal reduction in leaf size from south to north. Mean annual precipitation and an annual aridity index also significantly decreased and increased with latitude, respectively. It is suggested that the morphological cline is the result of plastic and/or adaptive responses to environmental conditions, and indicative of further ecophysiological latitudinal differences among Q. rugosa populations. Additionally, we estimated the magnitude of the least significant difference among populations for the first PC and translated it into a delineation of six latitudinal zones (each with a width of 2°30′), to be considered as preliminary zones for the movement of Q. rugosa seeds with management and conservation purposes, including management in response to global warming. 相似文献
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Akhil Ranjan Baruah Noriko Ishigo-Oka Mieko Adachi Yasuyo Oguma Yoshiro Tokizono Kazumitsu Onishi Yoshio Sano 《Euphytica》2009,165(3):459-470
The present study was conducted to understand the pattern of variation and the genetic bases for cold tolerance at the early
growth stage in Asian rice. The genetic variation was investigated at the germination, plumule and seedling stages among 57
strains including cultivated rice (Oryza sativa ssp. indica and ssp. japonica) and its wild progenitor (Oryza rufipogon). The significant differentiation of cold tolerance was observed among the taxonomically divided groups. At the germination
stage, both indica and japonica subspecies tended to be more tolerant than O. rufipogon, whereas at the plumule and seedling stages, ssp. japonica tended to be more tolerant than ssp. indica and O. rufipogon. Furthermore, in cold tolerance at the plumule stage, the clinal variation across the latitude of origins was observed within
O. rufipogon and ssp. japonica, suggesting that the current pattern of variation seems to have been shaped by both their phylogenetic histories and on-going
adaptation to the local environments. QTL analysis between O. sativa ssp. japonica (tolerant) and O. rufipogon (susceptible) revealed five putative QTLs for cold tolerance at the plumule and seedling stages but not at the germination
stage. Substitution mapping was also carried out to precisely locate the two major QTLs for cold tolerance at the plumule
stage, which could be used for improvement of tolerance to cold stress in ssp. indica. 相似文献
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在收集大量图纸资料的基础上,对黄、渤海区小型折线型木质渔船的空船质量及重心位置进行了统计分析,并提出了空船质量及重心位置的估算公式,供设计折线型木质淦船时参考。 相似文献
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The extent of genetic variation in seed length, width, thickness, weight and germination percentage and seedling traits among
and within 12 African provenances of Faidherbia albida was examined. The regional provenances showed a consistent variation
in seed length, seed width and seed weight: the southern African provenances had the largest seeds and west African provenances
the smallest. Seedling height, stem collar diameter and true leaf number differed (P = 0.05) among the provenances 90 days
after germination. The seedlings from west Africa were shorter, had smaller stem collar diameter and fewer leaves. In contrast,
the southern and east African provenances had taller seedlings with bigger seedling diameter and more leaves per seedling.
Seedling traits did not show clear-cut divisions between southern and east African provenances, but the west African provenances
formed a distinct group. Positive correlations were found in some of the seed characteristics and seedling height among provenances,
which could be an important criterion for early provenance selection. Greater variation was observed for seed and seedling
traits among than within provenances suggesting that selection among provenances might result in rapid genetic gain for the
traits studied.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Linas BALIAUSKAS Albina AMSHOKOVA Laima BALIAUSKIEN Ana Maria BENEDEK Jan CICHOCKI Alexander CSANDY Philippe Gil DE MENDONA Victoria NISTREANU 《Integrative zoology》2020,15(1):55-68
Patterns of body size variation along geographical gradients have long been searched for and generalized into eco‐geographical rules. However, no rodent species has yet been analyzed in relation to the 3 dimensions of latitude, longitude and altitude. We analyzed geographical clines and dimorphism of body and skull size in the herb field mouse (Apodemus uralensis) across the species range, based on field data and on data from the literature. Sexual dimorphism in adult A. uralensis was not expressed at a large scale, while local patterns were inconsistent. Age‐dependent size changes were most expressed in adult individuals: most characters of adults exceeded in size those of subadults, while subadult–juvenile size differences were only significant in body weight and length, zygomatic skull width, length of cranial diastema and breadth of braincase. Despite central morphological niches along the clines being separated, A. uralensis populations showed a high degree of size overlap in morphological space. We found the species to be characterized by high size variability, with the largest individuals inhabiting the eastern and southern edges of the distribution range. Tail, hind foot and ear lengths were largest in the southern part of the range, in agreement with Allen's rule. The main measurements that we analyzed, namely body mass, zygomatic skull width and condylobasal skull length, show the presence of 3 clines in the size of adult A. uralensis: (i) a decreasing south–north cline, opposing Bergmann's rule; (ii) an increasing west–east cline, in accordance with Murphy's rule; and (iii) an increasing altitudinal cline. 相似文献
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