Storage of Non-structural Carbohydrates in Sweet Sorghum [Sorghum bicolor (L.) Moench.]: Comparison of Sterile and Fertile Lines

The accumulation of soluble carbohydrates in vegetative parts of sweet sorghum ( Sorghum bicolor (L.) Moench.) represents an intermediate reserve pool for grain filling as well as an irreversible storage up to maturity. In order to study the effect of Sterility on soluble sugar accumulation in vegetative parts, two cytoplasmic male sterile (CMS) lines of sweet sorghum were compared with their corresponding fertile mamtainers for non-structural carbohydrate concentrations in shoots. Plants were harvested at four different physiological stages. The lines showed significant differences in the yield of non-structural carbohydrates. At maturity, the yields of soluble carbohydrates from vegetative parts of the two sterile lines were 93 % and 43 % higher than the yield of the two corresponding fertile lines. At that stage, sucrose represented about 80 % of total soluble carbohydrates and the higher yield of soluble carbohydrates of sterile lines was mainly due to the higher yield of sucrose. This indicates that the yield of extractable carbohydrates, especially sucrose, in vegetative parts of sweet sorghum could be considerably improved by using sterile lines which are utilized in hybrid production.     

甘孜藏牛mtDNA 基因组遗传多样性分析

［目的］探究甘孜藏牛的mtDNA基因组遗传多样性与母系起源。［方法］采用mtDNA全基因组序列比对及生物信息学方法。［结果］结果显示：在28头甘孜藏牛mtDNA 基因组中,共检测到1232个变异位点,确定了22种单倍型,其单倍型多样度（Hd）为0.98820±0.00010,核苷酸多样度（Pi）为0.02420±0.00003,表明甘孜藏牛具有丰富的母系遗传多样性。系统发育树和网络分布图表明,28头甘孜藏牛mtDNA基因组包括4种母系支系,分别为普通牛的T2、T3与T4支系,还有牦牛支系,其中T2支系占7.14%,T3支系占64.29%,T4支系占3.57%,牦牛支系占25 %。［结论］甘孜藏牛具有较丰富的母系遗传多样性,为普通牛母系起源,但与牦牛有杂交。     

苏钟猪和太湖猪的线粒体D环部分序列比较分析

测定了以太湖猪为母本的杂交一代苏钟猪21个个体线粒体D环序列442 bp,结合已报道的中国太湖猪两个类群(梅山猪和二花脸)的线粒体DNA控制区(D-loop)序列进行分析,结果表明:苏钟猪和太湖猪的聚类主要有两类,部分苏钟猪和大多数梅山猪分布在类群Ⅰ;少数梅山猪、苏钟猪和二花脸聚为类群Ⅱ.梅山猪在几支上都有分布,可能与梅山猪有大中小类型之分有关.这一结果与根据形态差异把太湖猪分成不同的类群相一致.     

猪瘟活疫苗(脾淋源)污染外源性兔出血症病毒的检测与启示

在进行2批猪瘟活疫苗（脾淋源）效力检验时,出现效力检验家兔突然死亡现象,为了查明家兔死亡原因,采用无菌检验、支原体检验、血凝试验、兔体中和试验、酶联免疫吸附试验（ELISA）对疫苗或注苗后死亡家兔肝脏、脾脏混合病料进行了检测。结果显示,疫苗的无菌检验、支原体检验结果均为阴性;疫苗及注射疫苗死亡家兔肝脏、脾脏混合病料具有较低的血凝价,血凝试验结果均为可疑;在兔体中和试验中,中和组家兔2／2健康存活,未中和的疫苗对照组家兔2／2死亡;疫苗及注射疫苗死亡后家兔肝脏、脾脏混合病料的ELISA检测结果均为阳性。检测结果证实疫苗中含有兔出血症病毒（Rabbit Haemorrhagic Disease Virus,RHDV）。猪瘟活疫苗（脾淋源）污染RHDV的现象启示：应该加强猪瘟活疫苗（脾淋源）抗原制备过程的控制;同时有必要对猪瘟活疫苗（脾淋源）质量标准进行修订使之进一步补充完善。     

马尾松地理起源及进化繁衍规律的探讨地

通过地史变迁、冰川影响、地形特点、生态条件的分析与植株原始形态的调查检测,提出四川盆地的马尾松种源是我国古老马尾松的原始类型。由于盆地的特殊地形,使马尾松渡过冰期的影响得以保存而生长到现在。经检测该地区马尾松针叶树脂道数目最少,只有大多数种源的一半,条叶型苗木比例最高,比大多数种源高 2-6倍。树脂道少与条叶型苗木多都是较为原始的形态特征,证明四川盆地种源属于原始类型,是马尾松地理起源种群。     

甘蓝型油菜波里马细胞质雄性不育与隐性细胞核雄性不育的遗传比较

甘蓝型油菜波里马细胞质雄性不育与隐性细胞核雄性不育受２套完全不同的基因系统控制。所被研究的波里马细胞质雄性不育的保持系和恢复系均带有隐性细胞核雄性不育的２对主效恢复基因Ｍｓ１和Ｍｓ２。２个隐性细胞核雄性不育系均是波里马细胞质雄性不育的保持系，不带有主效恢复基因Ｒｆｃ，但带有一定数目的温度敏感基因Ｔｓ。Ｍｓ１或Ｍｓ２与Ｒｆｃ是独立遗传的     

Embryo-mediated genome editing for accelerated genetic improvement of livestock

Selecting beneficial DNA variants is the main goal of animal breeding. However, this process is inherently inefficient because each animal only carries a fraction of all desirable variants. Genome editing technology with its ability to directly introduce beneficial sequence variants offers new opportunities to modernize animal breeding by overcoming this biological limitation and accelerating genetic gains. To realize rapid genetic gain, precise edits need to be introduced into genomically-selected embryos, which minimizes the genetic lag. However, embryo-mediated precision editing by homology-directed repair (HDR) mechanisms is currently an inefficient process that often produces mosaic embryos and greatly limits the numbers of available edited embryos. This review provides a summary of genome editing in bovine embryos and proposes an embryo-mediated accelerated breeding scheme that overcomes the present efficiency limitations of HDR editing in bovine embryos. It integrates embryo-based genomic selection with precise multi-editing and uses embryonic cloning with elite edited blastomeres or embryonic pluripotent stem cells to resolve mosaicism, enable multiplex editing and multiply rare elite genotypes. Such a breeding strategy would enable a more targeted, accelerated approach for livestock improvement that allows stacking of beneficial variants, even including novel traits from outside the breeding population, in the most recent elite genetic background, essentially within a single generation.     

Phytophthora urerae sp. nov., a new clade 1c relative of the Irish famine pathogen Phytophthora infestans from South America

An unknown Phytophthora species was discovered in the central Peruvian Andes on blighted foliage of the native South American plant species Urera lacineata. Urera is a genus of native flowering shrubs in the nettle family Urticaceae. This new taxon Phytophthora urerae sp. nov. is herewith formally described based on extensive morphological analysis, phylogenetic analysis of nuclear and mitochondrial loci, and AFLP analysis. Phytophthora urerae sp. nov. is a close relative of the Irish famine pathogen, Phytophthora infestans, and only the third clade 1c taxon described from South America to date. In contrast to the clade 1c taxon Phytophthora andina, first described in South America as a hybrid, P. urerae does not appear to be a hybrid based on cloning and sequencing nuclear loci. Findings of new species in South America may provide novel insights into the origin and evolutionary history of clade 1c Phytophthora species.