猪肉品质性状评定和遗传改良研究综述

本文针对猪肉品质在猪宰后才被确定的特殊性 ,从猪肉品质的定义出发 ,综述了猪肉品质指标的评定 ;并根据猪肉品质性状的中低遗传力特点 ,整体阐述了其遗传改良途径、现状和局限性     

杜洛克猪新品系肉质特性的初步研究

对杜洛克猪新品系1-4世代同胞测定猪各项肉质性状的测定研究表明,其PH值为6.4,系水力为89％,肌内脂肪含量为3.96％,色值为15％。各项肉质指标均在育种目标规定的正常范围内,且肌内脂肪含量较高,说明该品系具有良好的肉质;世代选育未导致肉质下降,还相应改善了肉质;性别对肉质无明显影响;肉质性状间的相关与聚类分析结果表明,肌肉PH值、系水力和色值是衡量肌肉品质优劣的主要指标,而水份与脂肪含量是反映肉质风味的重要指标;随着胴体品质提高呈现肉质下降的趋势。     

紫荆群体表型性状多样性研究

以紫荆全分布区的7个天然群体为研究试材,另取2个栽培群体为对照,对当年生枝的叶片、荚果、种子等14个表型性状进行比较分析,讨论群体间和群体内的表型多样性。结果表明,紫荆种内表型性状在群体间和群体内存在着极其丰富的变异。群体平均表型分化系数(VST)为32.30%,群体内的变异贡献大于群体间的。紫荆表型性状与生态因子相关分析表明,其种内群体表型变异呈梯度规律性,随着海拔的升高,叶片和种子逐渐变大;随着经纬度的增加,荚果形状从窄条形向宽条形变异,种子形状从近圆形向椭圆形变异。利用主成分分析对8个群体进行了排序、归类(其中P6群体性状值缺失比较多,故未进行排序),分析表明8个群体大致可以划为天然和栽培两类,天然群体又可分为两亚类。天然紫荆与栽培紫荆在表型上已经产生了分化。     

Microsatellite markers associated with lint percentage trait in cotton, Gossypium hirsutum

Molecular markers associated with fiber development traits have the potential to play a key role in understanding of cotton fiber development. Seventeen SSRs out of 304 markers tested from MGHES (EST-SSR), JESPR (genomic SSR), and TMB (BAC-derived SSR) collections showed significant linkage associations (using a Kurskal-Wallis non-parametric test) with lint percentage QTL in a set of recombinant inbred cotton lines (RILs) segregating for lint percentage. The permutation test of these potential markers associated with lint percentage QTL(s) determined that 12 SSR markers have stable estimates, exceeding empirically chosen threshold significance values at or above α = 0.01. Interval mapping demonstrated that 9 SSRs with stable critical LOD threshold values at α = 0.01 have significant QTL effect. Multiple QTL-mapping (MQM) revealed that at least, two highly significant fiber development QTLs exist around regions TMB0471 and MGHES–31 (explained about 23–59% of the phenotypic variation of lint percentage) and around markers MGHES–31 and TMB0366 (accounted for 5.4–12.5% phenotypic variation of lint percentage). These markers, in particular fiber-specific EST-SSRs, might be the possible ‘candidate’ loci contributing for fiber development in cotton. BAC-derived SSRs associated with fiber trait are the possible markers that are useful for the identification of physical genomic contigs that contain fiber development genes. Several lint percentage trait associated SSR markers have been located to chromosomes 12, 18, 23, and 26 using deletion analysis in aneuploid chromosome substitution lines. Outcomes of the work may prove useful in understanding and revealing the molecular basis of the fiber development, and the utilization of these markers for development of superior cotton cultivars through marker-assisted selection (MAS) programs. I. Y. Abdurakhmonov and S. Saha contributed equally to the work     

点播条件下早熟燕麦单株粒重与几个主要性状的相关性研究

在点播条件下，对４２个早熟燕麦材料７个性状的表现及其性状间的相关性进行了研究。结果表明：单株地上生物量和单株粒数的变异程度较大，株高和千粒重两性状的变异相对较小；单株地上生物量和单株粒数与单株粒重有极显著的正相关关系。通径分析表明单株地上生物量和单株粒数对单株粒重的直接效应较大，千粒重和株高对单株粒重的直接效应相对较小。     

群体规模和性状遗传力对F2设计下QTL定位效果的影响

 以F₂设计为资源群体，以区间定位分析为QTL定位的方法，通过计算机模拟，系统地比较了不同资源群体规模和性状遗传力下QTL检测效率,QTL位置和效应估计的准确性和精确性，以期揭示出两个因素对QTL定位效果影响的一般性规律。结果表明：适当扩大资源群体的规模，不仅有助于提高QTL的检测效率，而且还可提高QTL位置和效应估计的可靠性；当对高遗传力性状的QTL实施定位时，QTL的检测效率以及QTL位置估计的准确性和精确性相对较高，但QTL效应估计的可靠性则会有所降低。     

烟草六个重要性状的QTL定位

以烤烟台烟7号与白肋烟白肋21作为杂交亲本,后代自交衍生的127个F₂和F_2:3家系为材料,构建了全长3 483 cM包括26个连锁群、190个标记位点的烟草遗传连锁图谱。通过一年两地各3次重复的随机区组田间试验,测定烟叶烟碱、总氯、总钾、叶长、茎叶夹角、白粉病6个重要性状,采用混合线性模型的复合区间作图法定位QTL并分析其遗传互作效应。结果检测到2个烟碱相关QTL、2个总氯相关QTL、1个总钾相关QTL、4个叶长相关QTL、茎叶夹角和白粉病相关QTL各1个,其中6个加性效应QTL和4对加加上位性效应QTL。这11个基因位点遗传效应中除加性效应外,上位性效应也具有重要作用。     

香菇分子遗传连锁图谱研究进展

综述了香菇(Lentinula edodes)遗传连锁图谱构建的研究现状,对现有的连锁图所涉及的分子标记、作图群体、连锁群数量、图谱大小等进行了讨论,并对遗传连锁图谱意义和发展前景进行了分析与展望.     

Breeding and biotechnological efforts in Jatropha curcas L. for sustainable yields

Jatropha is a non-edible, important bioenergy plant, which can grow in marginalized land. The seeds possess about 36% oil and this would be converted into biodiesel or biojet-fuel. Jatropha provides an option for sustainable feed and fuel production due to its inherent qualities including hardy nature, drought tolerance and surviving with limited amount of water, tolerance to unfavorable conditions and excessive moisture. However, heterozygosity, low productivity and poor understanding of its genome are the major impediments to elite line development. Further, classical breeding and advanced technological investments remain limited owing to long juvenile phase and breeding cycles. Scientific technologies that lead to identification of elite genotypes and development of high yielding elite Jatropha lines and effective methods of detoxification of seeds needs immediate priority. Efficient tissue culture system, doubled haploids (DH) and genomic tools are increasingly made available to improve the seed yield and its oil quantity through the development of geminivirus disease resistant lines. The application of advanced, sequencing technologies has presented a repertoire of genomic information for this important yet orphan crop. In the present investigation, we highlight the achievements made in Jatropha towards development of high yielding, virus resistant elite lines and hybrids with yield potential ranging from 3 to 5 tons per hectare in a year, which is a first ever report in the world. We also developed potential biotechnological tools such as genetic transformation, genome editing and next generation genomics tools including linkage maps and QTLs for accelerating breeding efforts through marker assisted selection. Because of our concerted and continuous efforts during the past 15 years, we have overcome all the obstacles and developed high yielding, disease resistant hybrids/lines, advanced cultivation technologies with thorough knowledge on Agronomy of the Jatropha crop. The Jatropha cultivation technology developed for the first time in the world, could open up new avenues for higher yield productivity of commercial viability.     

98份燕麦品种性状变异的研究

[目的]介绍98份燕麦种质资源评价结果。[方法]从加拿大温尼伯农业研究分站引进的98份燕麦品种,种植在青海省畜牧科学院草原研究所试验田内,通过引种试验,研究了燕麦品种在西宁市的性状。[结果]品种间的性状差异很大,不同品种各性状最大与最小值的范围为：生育期109～138d,千粒重11.0～35.3g,茎粗0.32～0.71cm,株高141～210cm,叶长29～55cm,叶宽1.0～3.1cm,单株粒重4.45～15.03g,单株秸秆重9.60～24.78g。株高、生育期和产量三者之间呈正相关关系。18个相同品种的燕麦,在西宁市的平均生育期较在加拿大温尼伯站长20.1d,株高平均增加75.8cm。[结论]引进的98份燕麦品种均能适应西宁市地区的气候条件,生长发育良好,从中初步筛选出20份性状表现较好的品种作进一步观察筛选。