An allelic series at the Co-1 locus conditioning resistance to anthracnose in common bean of Andean origin

In this study, we characterized the genetic resistance of the Andean bean cultivars Kaboon and Perry Marrow and their relation to other sources of anthracnose resistance in common bean. Based on the segregation ratio (3R:1S) observed in two F₂ populations we demonstrated that Kaboon carries one major dominant gene conferring resistance to races 7 and 73 of Colletotrichum lindemuthianum. This gene in Kaboon is independent from the Co-2 gene and is an allele of the Co-1 gene present in Michigan Dark Red Kidney (MDRK) cultivar. Therefore, we propose the symbol CO-1 ² for the major dominant gene in Kaboon. The Co-1 is the only gene of Andean origin among the Co anthracnose resistance genes characterized in common bean. When inoculated with the less virulent Andean race 5, the segregation ratio in the F₂ progeny of Cardinal and Kaboon was 57R:7S (p = 0.38). These data indicate that Kaboon must possess other weaker dominant resistance genes with a complementary mode of action, since Cardinal is not known to possess genes for anthracnose resistance. Perry Marrow, a second Andean cultivar with resistance to a different group of races, was shown to possess another resistant allele at the Co-1 locus and the gene symbol Co-1 ³ was assigned. In R × R crosses between Perry Marrow and MDRK or Kaboon, no susceptible F₂ plants were found when inoculated with race 73. These findings support the presence of a multiple allelic series at the Andean Co-1 locus, and have major implications in breeding for durable anthracnose resistance in common bean. This revised version was published online in July 2006 with corrections to the Cover Date.     

熊有管与无管取胆的对比分析

对某熊场的胆粉产量作统计，无管取胆胆粉产量的累计绝对值在有管前4年和前5年之间，有管处理的前4年产值相对略低，而与长期产值相比明显高．有管取胆的引流系数，每只年产、日产绝对值，年产、日产累计绝对值，每头年产累计实产值等，随取胆年限趋于逐渐下降。而胆囊报废、熊只死亡、采胆空白率（停产）均呈逐年上升．使产值逐年下降的最重要的因素是熊只死亡，报废因素占第2位，故障等其他因素占次要地位．     

角接触轴承的配置方式

由于常用的锁口在外圈的角接触轴承,配置方式可按两轴承外圈的宽窄边相对来划分;对锁口在内圈的单列角接触球轴承,由于其结构的特殊性,其配置方式不能按两轴承外圈的宽窄边相对来划分。为此,对单列角接触轴承的配置方式进行了探讨;并介绍了单列角接触轴承划分配置方式的统一方法。     

Population viability and perturbation analyses in remnant populations of the Andean catfish Astroblepus ubidiai

Abstract – Astroblepus ubidiai (Actinopterygii; Siluriformes), which is the only native fish of the highlands of the Province of Imbabura, Ecuador, was abundant in the past in the Imbakucha watershed and adjacent drainages but currently it is restricted to a few isolated refuges. Population viability analysis (PVA) was used to detect critical aspects in the ecology and conservation biology of this unique fish. The annual population growth rate ( λ ) was estimated for six remnant populations of this Andean catfish using a deterministic matrix population model. Sensitivity and elasticity analyses complemented the PVA by providing constructive insights into vital rates affecting projections and extinction probabilities. Positive population growth rates were found in all the study populations. The high contributions of juvenile survival to the variance of λ and its high elasticity indicated that A. ubidiai population dynamics are highly sensitive to the transition values of this vital rate, which can promptly respond to management or antagonistic perturbations. Allowing fish to survive until the age of first reproduction and permitting the successful reproduction of these individuals will facilitate positive population growth rates, however the very small areas of occupancy, small extent of occurrence and severe fragmentation may still contribute to the extinction risk.     

小兴安岭南坡黑熊植物性食物营养分析

2007年4月～2008年11月,在小兴安岭南坡龙口自然保护区,共设置1725个小样方,收集黑熊春、夏、秋季可获得的植物性食物21种。并对其进行营养测定,得到黑熊植食性食物夏季的粗蛋白质含量最高,粗脂肪含量最低,秋季粗纤维含量最高。对营养含量进行差异性检验,结果表明：粗脂肪含量在春夏季和夏秋季差异均显著（P〈0.05）,其他营养含量各季节之间差异均不显著。     

群养棕熊饲养管理难点剖析

棕熊在野生动物园中大种群混养,饲养管理难度大,结合秦皇岛野生动物园这几年的饲养管理经验,从馆舍设计、相残行为、饲养繁殖等几个方面难点进行剖析,以利于更好地提高棕熊大种群混养水平。     

Pollination requirements for seed set in ulluco (Ullucus tuberosus)

Summary Pollination experiments were carried out on ulluco (Ullucus tuberosus), known as a very poor seed producer. All the clones used were diploids. The effect of self-vs. cross-pollination was studied in Experiment 1. Caged selfpollinated flowers produced no seeds. Different clones produced seeds in 0–8% of caged cross-pollinated flowers and in 5–19% of cross-pollinated non-caged flowers. Ulluco is thus basically an outbreeder.Experiment 2 studied whether seed set is limited by pollen availability. Total seed number per inflorescence number did not differ between plants treated with supplemental pollen and control plants; pollen availability thus did not limit seed set. The treated plants, however, produced more seeds in cross-pollinated than in other flowers on the plant, and the control flowers on treated plants produced fewer seeds than those on the control plants. In the treated plants, resources may have been allocated to artificially cross-pollinated flowers at the expense of other flowers. In some clones, seed set after artificial cross-pollination was at a level practicable for breeding work.     

A preliminary study of the genetic diversity of Bolivian oca (<Emphasis Type="Italic">Oxalis tuberosa</Emphasis> Mol.) varieties maintained<Emphasis Type="Italic"> in situ</Emphasis> and<Emphasis Type="Italic"> ex situ</Emphasis> through the utilization of ISSR molecular markers

ISSR molecular markers have been used to investigate genetic diversity of oca (Oxalis tuberosa Mol.), an Andean neglected tuber crop species. Sampling procedure allowed a preliminary study of the genetic diversity at the intra- and intervarietal levels. Twenty tuber lots conserved in situ in the microcentre of Candelaria and ex situ in the Toralapa Centre (Bolivia) were identified. Four ISSR primers amplified a total of 25 fragments of which 17 (68%) were polymorphic. These experiments show that the structure of oca varieties is mainly based upon vernacular names with a greater differentiation among tuber lots than within them, supporting agromorphological data. ISSR technique enlightened the existence of heterogeneous varieties in oca and divergence between in situ and ex situ conservation strategies. These observations are potentially linked to the different ways of management of tubers in these two conservation systems.     

Landscape conditions predisposing grizzly bears to conflicts on private agricultural lands in the western USA

We used multiple logistic regression to model how different landscape conditions contributed to the probability of human-grizzly bear conflicts on private agricultural ranch lands. We used locations of livestock pastures, traditional livestock carcass disposal areas (boneyards), beehives, and wetland-riparian associated vegetation to model the locations of 178 reported human-grizzly bear conflicts along the Rocky Mountain East Front, Montana, USA during 1986-2001. We surveyed 61 livestock producers in the upper Teton watershed of north-central Montana, to collect spatial and temporal data on livestock pastures, boneyards, and beehives for the same period, accounting for changes in livestock and boneyard management and beehive location and protection, for each season. We used 2032 random points to represent the null hypothesis of random location relative to potential explanatory landscape features, and used Akaike’s Information Criteria (AIC/AIC_C) and Hosmer-Lemeshow goodness-of-fit statistics for model selection. We used a resulting “best” model to map contours of predicted probabilities of conflict, and used this map for verification with an independent dataset of conflicts to provide additional insights regarding the nature of conflicts. The presence of riparian vegetation and distances to spring, summer, and fall sheep or cattle pastures, calving and sheep lambing areas, unmanaged boneyards, and fenced and unfenced beehives were all associated with the likelihood of human-grizzly bear conflicts. Our model suggests that collections of attractants concentrated in high quality bear habitat largely explain broad patterns of human-grizzly bear conflicts on private agricultural land in our study area.     

Density and population size estimates for North Cascade grizzly bears using DNA hair-sampling techniques

We used non-invasive DNA hair-sampling and catch per unit effort (CPUE: grizzly bears detected per 1000 trap nights) to estimate relative density and population size for a threatened grizzly bear population in the North Cascade Ecosystem of Washington and British Columbia. We used linear, logistic, and linear through the origin regression analyses to estimate the relationship between catch per unit effort and grizzly bear density for seven other grizzly populations. One grizzly bear was detected during 5304 trap nights (CPUE=0.19) over 3 years in the North Cascades. This CPUE was much lower than in the other seven populations, including two threatened grizzly populations in the Cabinet-Yaak and Selkirk Mountain Ecosystems. The logistic model (curvilinear relationship) best fit the data (R²=0.927), and yielded density and population size estimates of 0.15 bears/100 km² (90% CI=0.03-0.71) and six bears (90% CI=1-27), respectively. Natural recovery seems unlikely for the North Cascade grizzly bear population because the population has a high likelihood of extinction due to demographic and environmental stochastic effects associated with extremely small population numbers. We recommend population augmentation. DNA hair-sampling and catch per unit effort models can be a useful method to evaluate relative densities and numbers of animals in small, threatened grizzly bear populations when sample sizes are too small to yield traditional mark-recapture analysis.