SSR markers for a critically endangered species Euryodendron excelsum and a distantly related species Ternstroemia gymnanthera (Ternstroemiaceae)

Euryodendron excelsum is a critically endangered tertiary relict plant endemic to China. It has only one population remaining in Ba Jia Zhen of Yangchun, Guangdong. In this study, we discovered 25 microsatellite markers from E. excelsumusing a Fast Isolation by Amplified Fragment Length Polymorphism of Sequences COntaining Repeats (FIASCO) protocol. Thirteen loci demonstrated polymorphisms, with the number of alleles per locus ranging from 2 to 13. Values for observed and expected heterozygosity ranged from 0.176 to 1.000 and from 0.261 to 0.889, respectively. Three loci (ZXM-17, ZXM-54, and ZXM-92) were found to significantly deviate from Hardy-Weinberg equilibrium. In addition, five of 13 loci could be successfully cross-amplified in Ternstroemia gymnanthera. These microsatellite loci may help to further survey the adaptive evolution and genetic variation of E. excelsum for guiding its conservation.     

Genetic assessment of captive Chinese water deer populations in Zhoushan Archipelago,China

Chinese water deer is a rare and vulnerable animal in China because of the poaching for medical use and the habitat loss. In this study, the genetic diversity and population genetic structure of 40 Chinese water deer from three populations in Zhoushan Archipelago were investigated with ten highly polymorphic microsatellite loci, including 4 screened from the nuclear DNA in the study, and 6 selected from the literature. According to the results, these captive populations had a higher genetic diversity than other rare cervid species, such as forest musk deer. No signs of inbreeding were detected. Low genetic differentiation among these populations was found. The probable reasons included the isolation by distance, the exchange among islands, or the supplement of the wild Chinese water deer. We proposed the deer raisers to strengthen the exchanges from different islands or mainland, and if possible, some deer would be returned to the wild to expand the wild population.     

Isolation and characterization of polymorphic microsatellite loci in Indian major carp,Catla catla using next-generation sequencing platform

Catla catla, the second most important Indian major carp, is gaining its popularity among Indian fish farmers due to its high growth rate and consumer preferences. Simple sequence repeats (SSRs) are rapidly evolving, versatile, co-dominant and highly informative molecular markers used in genetic research. However, the time and cost involved in developing such resources has limited their extensive use. Advent of massive parallel sequencing technology has considerably eased these limitations. In the present investigation, we used Ion Torrent sequencing platform to identify potentially amplifiable microsatellite loci for catla. A modest sequencing volume generated approximately 5.7 MB of sequence data. Out of 29,794 sequences generated, 21,477 contained simple sequence repeats. Only 81 sequences had enough flanking sequences for primer designing. Out of 81 loci, 51 were successfully PCR amplified in a panel of five unrelated individuals. Out of 15 loci randomly checked for polymorphism, 13 loci were polymorphic with allele number ranged from 3 to 6 and two loci were found to be monomorphic. The observed and expected heterozygosities ranged from 0.565 to 0.870 and 0.483–0.804, respectively. These markers will be useful for studying genetics of wild populations, breeding programs of C. catla and closely related species.     

Profiling of selected indigenous rice (Oryza sativa L.) landraces of Rarh Bengal in relation to osmotic stress tolerance

A total of ten rare indigenous rice landraces of West Bengal were screened for germination potential and seedling growth under varying concentrations of sodium chloride (NaCl) and polyethylene glycol (PEG) solutions as osmotic stress inducing agents. Among the studied rice landraces Kelas and Bhut Moori showed highest degree of tolerance to induced osmotic stresses. Proline content of the studied lines was also determined. Genetic relationship among the studied rice landraces was assessed with 22 previously reported osmotic stress tolerance linked Simple Sequence Repeat (SSR) markers. The identified allelic variants in form of amplified products size (molecular weight) for each SSR marker were documented to find out allele mining set for the linked markers of the studied genotypes in relation to osmotic stress tolerance. A Microsatellite Panel was constructed for the different allelic forms (size of amplified products) of each used marker. Among 22 SSR markers, ten showed unique alleles in form of single specific amplified product for the studied four genotypes which can be used for varietal identification. Genetic relationship among the studied rice lines was determined and a dendrogram was constructed to reveal their genetic inter-relationship. Polymorphism Information Content (PIC) for each used marker was also calculated for the studied rice lines.     

中国圈养林麝微卫星DNA多样性研究

本文利用13对微卫星标记,对我国3个核心种源地（巴山、秦岭、川西高原）圈养林麝种群进行遗传多样性和遗传结构分析。在167份样品中共检测到142个等位基因（Na）,每个位点等位基因数介于7~16,均值为10.92,平均有效等位基因数（Ne）为6.3730,期望杂合度（He）和观测杂合度（Ho）均值分别为0.8302和0.3897。这些圈养林麝种群遗传多样性水平较高,但较低的观测杂合度表明圈养群体存在近交现象。两两群体间的Fst 值和AMOVA分析结果均表明种群之间分化程度不明显。群体遗传结构分析显示,全部样本聚为3个遗传簇（最佳K值=3）,其主体与3个地理来源相符,但种群间存在基因渗透现象。本研究中的秦岭种群遗传变异最为丰富,可以作为种质改良的基因池。     

微卫星标记在大熊猫研究中的应用进展

大熊猫是我国保护最为成功、研究最为深入的珍稀动物之一,可以为其它珍稀濒危物种的保护研究工作提供参考。20世纪70年代末期借助无线电颈圈,大熊猫的生态学研究工作取得了突破性进展,近20年来微卫星标记和非损伤性遗传取样技术的联合使用,将大熊猫的保护研究工作提升到一个崭新的高度。本文在综合所有已发表大熊猫微卫星标记的基础上,梳理了微卫星标记在圈养大熊猫亲子鉴定与遗传管理,野生大熊猫个体识别与种群数量调查、遗传多样性评估、扩散和种群遗传结构研究中的应用情况,并着重介绍了其中29个重要的微卫星标记。同时指出目前微卫星标记的使用存在标记选择不统一、等位基因读数无统一规程等问题,并对应用前景进行了前瞻。