Correlation and path analysis of morphological and weight traits in marine gastropod Glossaulax reiniana

Using correlation and path analysis, the genetic correlation between weight traits and morphological traits was determined in the marine gastropod Glossaulax reiniana. A total of 100 G. reiniana individuals from a wild population were used. Shell width( X 1), shell height( X 2), umbo-callus height( X 3), body width( X 4), operculum length( X 5), operculum width( X 6), body weight( Y 1) and soft-tissue weight( Y 2) were measured, and the correlation coefficient matrix calculated. Morphological traits were used as independent variables and weight traits as dependent variables for path coefficient analysis. Path coefficients, correlation indices and determination coefficients were also determined. Results indicate that the correlation coefficients associated with each morphological and weight trait were all highly significant( P <0.01). After deleting redundant independent variables, the following optimum multiple regression equations were obtained using stepwise multiple regression analysis: Y 1 =- 29.317+0.362 X 2 +0.349 X 4 + 1.190 X 5 for body weight; and Y 2 =- 17.292+0.166 X 1 +0.171 X 2 +0.703 X 5, for soft-tissue weight. Operculum height had the highest positive direct correlation with both body weight and soft-tissue weight, which was in accordance with the test results obtained from determinate coefficient analysis. The indication of high genetic correlations between weight traits and morphological traits will provide valuable information for G. reiniana breeding programs.

Relationships between body weight and other morphological traits in young sea cucumbers Apostichopus japonicas

Correlation, multiple regression, and path analyses were used to investigate the relationships between body weight and three other morphological traits in juvenile Japanese sea cucumbers Apostichopus japonicus . We measured live body weight (BW), body length (BL), numbers of papillae (NP), and numbers of tube feet (NF) at 60, 80, 100, and 130 days post-hatching (dph). We calculated path correlation coefficients, correlation indices ( R 2 ), and coefficients of determination with BW as the dependent variable and the other morphological traits as independent variables. The coefficient of variation for BW was high across all age groups, and all measured morphological traits were significantly correlated ( P < 0.01). BL had the greatest direct eff ect on BW across all age groups (60 dph, 0.526;80 dph, 0.404;100 dph, 0.620;and 130 dph, 0.681), while NF had the greatest indirect eff ect on BW across all age groups (60 dph, 0.528;80 dph, 0.452;100 dph, 0.666;and 130 dph, 0.603). Regression analyses between morphological traits and BW indicated that R 2 was greater than 0.85 only in the 100-dph specimens. The indirect eff ects of the other measured morphological traits on BW were age-dependent. The optimal regression equations, as determined with stepwise regression, were, for 60-dph specimens: BW 60 =10 (-3.04+0.092BL+0.014NP+0.014NF)( R 2 =0.632);for 80-dph specimens: BW 80 =10 (- 3.035+0.056BL+0.017NP+0.02NF)( R 2 =0.686);for 100-dph specimens: BW 100 =10 (- 3.742+0.069BL+0. 633 · lg (NP)+0. 464 · lg (NF))( R 2 =0.893);and for 130-dph specimens: BW 130 =10 (- 2.472+0.065BL+0.012NP)( R 2 =0.774). Our work clarified the correlation between various morphological traits and body weight of a commercially-important sea cucumber species ( A . japonicus ). Our predictive models for body weight might be useful for the aquaculture and selective breeding of A . japonicus . These models might also provide theoretical support for the indirect selection of traits that are difficult to select directly.

Genome-Wide Association Study for Certain Carcass Traits and Organ Weights in a Large White×Minzhu Intercross Porcine Population

Porcine carcass traits and organ weights have important economic roles in the swine industry. A total of 576 animals from a Large White×Minzhu intercross population were genotyped using the Illumina PorcineSNP60K Beadchip and were phenotyped for 10 traits, speciifcally, backfat thickness （6-7 libs）, carcass length, carcass weight, foot weight, head weight, heart weight, leaf fat weight, liver weight, lung weight and slaughter body weight. The genome-wide association study （GWAS） was assessed by Genome Wide Rapid Association using the mixed model and regression-genomic control approach. A total of 31 single nucleotide polymorphisms （SNPs） （with the most signiifcant SNP being MARC0033464, P value=6.80×10-13） were located in a 9.76-Mb （31.24-41.00 Mb） region on SSC7 and were found to be signiifcantly associated with one or more carcass traits and organ weights. High percentage of phenotypic variance explanation was observed for each trait ranging from 31.21 to 67.42%. Linkage analysis revealed one haplotype block of 495 kb, in which the most signiifcant SNP being MARC0033464 was contained, on SSC7 at complete linkage disequilibrium. Annotation of the pig reference genome suggested 6 genes （GRM4, HMGA1, NUDT3, RPS10, SPDEF and PACSIN1） in this candidate linkage disequilibrium （LD） interval. Functional analysis indicated that the HMGA1 gene presents the prime biological candidate for carcass traits and organ weights in pig, with potential application in breeding programs.

Effects of Morphological Traits on Total Weight of Clam Meretrix lamarchii

Clam Meretrix lamarchii is delicious seafood with high economic value. The M. lamarchii in present market is mainly collected from wild population due to the lack of large-scale artificial seed production. In 2013,we carried out the artificial seedling exploration of M. Lamarchii. The current study utilized several statistical methods to analyze the effects of morphological traits on M. Lamarchii,which may provide knowledge for clam quality seedlings breeding work. The samples of M. Lamarchii were randomly sampled from Donghai Island,Zhanjiang. Shell length（ SL）,shell width（ SW）,shell height（ SH）,ligament length（ Li L）,lunule length（ Lu L） and total weight（ TW） of two-year-old M. Lamarchii were measured. A correlation coefficient matrix was constructed based on the results,where the total weight was set as the dependent variable and others as independent variables. Path coefficient and correlation index were calculated,and the major phenotypic characters were determined. The results showed that all the correlation coefficients between independent variables and dependent variable were significant（ P < 0. 01）,with an exception of the lunule length（ P > 0. 05）. The effects of the shell length,shell width,and shell height on the total weight were significant（ P < 0. 01）,and the shell length had dominant effect on the weight as a key effective factor. The multiple regression equation between the weight and the other traits was established as Y;=- 126. 784 + 1. 249X;+ 2. 036X;+ 0. 911 X;,where YWis total weight,X;,X;and X;are the shell length,shell width and shell height,respectively. The current study may contribute to the artificial breeding of the species.

Genetic analysis for brix weight per stool and its component traits in sugarcane (Saccharum officinarum)

Brix weight per stool (BW) of sugarcane is a complex trait, which is the final product of a combination of many components. Diallel cross experiments were conducted during a period of two years for BW and its five component traits, in- cluding stalk diameter (SD), stalk length (SL), stalk number (SN), stalk weight (SW), and brix scale (BS) of sugarcane. Phenotypic data of all the six traits were analyzed by mixed linear model and their phenotype variances were portioned into additive (A), dominance (D), additive×environment interaction (AE) and dominance×environment interaction (DE) effects, and the correlations of A, D, AE and DE effects between BW and its components were estimated. Conditional analysis was employed to investigate the contribution of the components traits to the variances of A, D, AE and DE effects of BW. It was observed that the heritabilities of BW were significantly attributed to A, D and DE by 23.9%, 30.9% and 28.5%, respectively. The variance of A effect for BW was significantly affected by SL, SN and BS by 25.3%, 93.7% and 17.4%, respectively. The variances of D and DE effects for BW were also significantly influenced by all the five components by 5.1%～85.5%. These determinants might be helpful in sugarcane breeding and provide valuable information for multiple-trait improvement of BW.

Fine-Mapping of qTGW1.2a, a Quantitative Trait Locus for 1000-Grain Weight in Rice

Thousand-grain weight (TGW) is a key component of grain yield in rice. This study was conducted to validate and fine-map qTGW1.2a, a quantitative trait locus for grain weight and grain size previously located in a 933.6-kb region on the long arm of rice chromosome 1. Firstly, three residual heterozygotes (RHs) were selected from a BC2F11 population of the indica rice cross Zhenshan 97 (ZS97)///ZS97//ZS97/Milyang 46. The heterozygous segments in these RHs were arranged successively in physical positions, forming one set of sequential residual heterozygotes (SeqRHs). In each of the populations derived, non-recombinant homozygotes were identified to produce near isogenic lines (NILs) comprising the two homozygous genotypes. The NILs were tested for grain weight, grain length and grain width. QTL analyses for the three traits were performed. Then, the updated QTL location was followed for a new run of SeqRHs identification-NIL development-QTL mapping. Altogether, 11 NIL populations derived from four sets of SeqRHs were developed and used. qTGW1.2a was finally delimitated into a 77.5-kb region containing 13 annotated genes. In the six populations segregating this QTL, which were in four generations and were tested across four years, the allelic direction of qTGW1.2a remained consistent and the genetic effects were stable. For TGW, the additive effects ranged from 0.23 to 0.38 g and the proportions of phenotypic variance explained ranged from 26.15% to 41.65%. These results provide a good foundation for the cloning and functional analysis of qTGW1.2a.

Mapping of qTGW1.1,a Quantitative Trait Locus for 1000-Grain Weight in Rice (Oryza sativa L.)

1000-grain weight （ TGW） is one ot the three component traits ot the grain yiela in rice （Oryza sativa L）. This study was conducted to validate and fine-map qTGWl. 1, a minor QTL for TGW which was previously located in a 3.7-Mb region on the long arm of rice chromosome 1. Five sets of near isogenic lines （NILs） were developed from two BC2F4 populations of the indica rice cross Zhenshan 973/Milyang 46 The NIL sets consisted of two homozygous genotypic groups differing in the regions RM11448-RM11522, RM11448-RM11549, RM1232-RM11615, RM11543-RM11554 and RM11569-RM11621, respectively. Four traits, including TGW, grain length, grain width and heading date, were measured. Phenotypic difference between the two genotypic groups in each NIL population was analyzed using SAS procedure GLM. Significant QTL effects were detected on TGW with the Zhenshan 97 allele increasing grain weight by 0.12 g to 0.14 g and explaining 8.30% to 15.19% of the phenotypic variance. Significant effects were also observed for grain length and width, whereas no significant effect was found for heading date. Based on comparison among the five NILs on the segregating regions and the results of QTL analysis, qTGWl. 1 was delimited to a 376.9-kb region flanked by DNA markers Wn28382 and RMl1554. Our results indicate that the effects of minor QTLs could be steadily detected in a highly isogenic background and suggest that such QTLs could be utilized in the breeding of high-yielding rice varieties.

芥菜型油菜AHK家族成员的全基因组鉴定及调控粒质量性状的初步探索

为探究芥菜型油菜AHK家族蛋白的结构特征及其与粒质量性状相关的调控功能,采用生物信息学方法对芥菜型油菜AHK家族成员进行了全基因组鉴定、理化性质、系统发育树、蛋白结构、启动子顺式元件和不同组织表达谱等分析。结果表明,在芥菜型油菜基因组中共鉴定到19条BjAHK蛋白序列,系统发育树分析将BjAHK家族成员分为了4个分支,即G1(BjAHK2~BjAHK4)、G2(BjAHK5)、G3(BjAHK1)和G4(BjCKI1)。功能结构域研究发现,BjAHK家族成员具有6个核心基序(Motif1~Motif6),与HisKA、HATPase_c和REC保守结构域相对应,其中BjAHK1~BjAHK4和BjCKI1蛋白的N端含有较为保守的跨膜结构域,可能与其跨膜作用功能有关。不同组织表达谱研究发现,细胞分裂素受体蛋白基因(BjAHK2~BjAHK4)为泛表达基因,且在根组织中表达量最高。结合已有的芥菜型油菜粒质量性状转录组数据,成功挖掘出4个可能参与粒质量性状调控的基因BjA07.AHK3、BjB03.AHK3、BjA10.AHK5和BjB05.AHK5。其中,BjA07.AHK3和BjB03.AHK3可能正向调控种子发育,而BjA10.AHK5和BjB05.AHK5则负向调控。结合BjAHK基因家族分析和转录组测序结果,推测BjAHK3和BjAHK5基因在调控芥菜型油菜种子发育方面发挥重要功能。

铜锈环棱螺形态性状对体质量的影响分析

为探究铜锈环棱螺不同群体主要形态性状间的相关性及影响其体质量的主要因素,随机选取微山湖、东平湖、骆马湖、洪泽湖、长江江都区段和滇池的野生铜锈环棱螺,测量其壳高、壳宽、壳厚、壳口长、壳口宽及体质量,采用相关分析与通径分析方法,并建立体质量的最优多元回归方程。试验结果显示,壳厚与体质量相关性不显著,壳高、壳宽、壳口宽和壳口长均与体质量相关性极显著。6个群体的决定系数总和分别为0.916、0.927、0.794、0.886、0.810和0.783,表明已分析出影响体质量的大部分形态性状。铜锈环棱螺体质量性状的主要影响因素在6个群体中并不相同,其中壳高或壳宽对体质量的影响作用比较大,是铜锈环棱螺体质量的主要影响因素。经多元回归方差分析和偏回归系数显著性检验,偏回归系数极显著(P<0.01)。本试验结果可为铜锈环棱螺的品种选育提供参考依据。

荒漠草原植物在氮磷添加下叶功能性状特征及其可塑性

探究荒漠草原植物在N、P添加下叶功能性状特征及其变异,对揭示植被对环境的响应机制至关重要。以宁夏盐池县荒漠草原植物群落为研究对象,分析了N、P添加对植物群落叶片形态和化学性状的影响。结果表明:植物群落叶片氮磷比<14,表明研究区植物生长受到N限制,P添加对植物群落叶片功能性状无显著影响,N+P共同添加显著增加了叶片碳磷比,N添加下植物群落叶面积、比叶面积、叶组织密度和叶片氮含量显著上升,反映了植物在环境的变化下采取了较快的养分循环策略;根据可塑性指数排序结果可知,植物群落叶面积、比叶面积、叶片干物质含量、叶组织密度、叶片碳含量和叶片氮含量为响应N、P添加的敏感性状(PI>0.5),其中变异性较大的性状为叶面积、比叶面积和叶组织密度,表明植物群落主要通过改变自身形态来应对环境的变化;相关性分析结果表明,植物群落叶片性状之间存在显著的相关性,并且表现出应对养分环境变化的协同作用。本研究为预测植物和生态系统对全球变化因素的反应提供了理论依据,对探讨区域植被分布、恢复进程至关重要。

饲粮粗蛋白水平对1~6周龄盐津乌骨鸡体重和体尺性状的影响

试验旨在研究饲粮粗蛋白水平对1~6周龄盐津乌骨鸡体重和体尺性状的影响。选取1日龄健康、体重相近的盐津乌骨鸡120只,随机分为3组,每组5个重复,每个重复8只鸡,分别饲喂粗蛋白水平为18.59%、20.09%和21.37%的试验饲粮。试验期6周。结果表明,1周龄时,21.37%组体重极显著高于18.59%组、20.09%组(P<0.01);3周龄时,20.09%组、21.37%组体重显著高于18.59%组(P<0.05)。饲粮粗蛋白水平对1周龄盐津乌骨鸡的平均日增重、料重比具有极显著影响(P<0.01),对3周龄平均日增重具有显著影响(P<0.05)。21.37%组1周龄体斜长、龙骨长、胫长、体高显著或极显著低于18.59%组(P<0.05或P<0.01);20.09%组2周龄胸宽显著高于18.59%组(P<0.05);21.37%组3周龄体斜长、胸深显著或极显著高于18.59%组(P<0.05或P<0.01);21.37%组4周龄胸宽显著高于18.59%组(P<0.05);21.37%组5周龄体斜长、龙骨长、副翼羽长显著高于18.59%组(P<0.05)。在6周龄时,18.59%组盐津乌骨鸡体重与体尺性状、羽毛性状的相关程度为胫长>体斜长>龙骨长>盆骨宽>主翼羽数>胸深>副翼羽长>体高>主翼羽长>胫围>胸宽(R=-0.004~0.885);20.09%组盐津乌骨鸡体重与体尺性状、羽毛性状的相关程度为体高>胸深>副翼羽长>龙骨长>主翼羽数>胸宽>体斜长>胫围>胫长>盆骨宽>主翼羽长(R=0.326~0.805);21.37%组盐津乌骨鸡体重与体尺性状、羽毛性状的相关程度为体斜长>胸深>胫围>胸宽>龙骨长>盆骨宽>体高>副翼羽长>主翼羽长>胫长>主翼羽数(R=-0.051~0.873)。研究表明,饲粮粗蛋白水平为21.37%时,1~6周龄盐津乌骨鸡的生长发育性能较好;饲粮粗蛋白水平为20.09%时,6周龄体重与体尺性状、羽毛性状指标相关性较好。

澳洲白羊生长和繁殖性状的遗传评估

该研究旨在评估澳洲白羊的生长和繁殖性状的遗传特性,为科学选育、良种扩繁和提高优良特性提供理论基础。在对生长性状(初生重、 90天体重、 180天体重、 240天体重、 0~90 d日增重、 90~240 d日增重)和繁殖性状(头胎产羔数、经产羔羊数、头胎窝均重、经产窝均重、头胎窝总重、经产窝总重)进行遗传评估时,使用R包AEFchida建立动物线性混合模型,进行方差组分、遗传参数、遗传相关性和育种值的估计;对于初生重,根据不同母体效应,运用R(v4-1-1)包AEFchida,比较了6种随机效应不同的动物线性混合模型。结果表明,考虑个体加性效应、母体环境效应和母体遗传效应的模型BW1为最优模型,计算初生重遗传力为(0.33±0.04)。繁殖性状在0.03~0.12为低遗传力,其中活羔数(头胎、经产)的遗传力在0.03~0.04,而生长性状在0.33~0.77之间为高遗传力,其中日增重(0~90日、 90~240日)的遗传力在0.46~0.67。产羔数与生长性状相关性较低(0~0.25),初生重与生长性状相关性适中(0.14~0.64),且表型相关性和遗传相关性基本一致。生长性状的育种均值随着年份的增加,整体呈上升趋势;繁殖性状的育种均值则变化幅度较小,选育效果不明显。可见,澳洲白羊繁殖性状和生长性状遗传特性相差较大,应采用不同的选育方式来进一步优化澳洲白羊的生产性能和遗传特性。

太行肉牛育种指数构成分析

对应太行肉牛育种实践,综合分析太行肉牛新品种选育的目标性状以及各性状在总性能指数构成中的权重。太行肉牛新品种选育的总性能指数由体型结构、适应性、生长发育、繁殖力、泌乳力及牛肉指数等六大目标性状构成,权重分别为16%、18%、25%、25%、6%和10%。同时描述了各目标性状的具体度量与数据采集方法。以期业界同仁共同探讨、批评指正,合力推进太行肉牛的育种进程。

12种竹子的叶表型变异及其与环境因子的关系

为了解不同竹种的叶表型变异特点及其受环境因子的影响,筛选出与抗寒性相关的叶表型性状,选取并测定分布在河南博爱和山东青岛的12种竹子的叶表型性状(长、宽、厚、长/宽、鲜质量、饱和鲜质量和干质量),进行变异分析、主成分分析、性状与环境因子的相关性分析并解析性状间的异速生长关系。结果表明,由博爱引至青岛后(温度降低但降雨量增加),蓉城竹和筠竹的叶表型性状在两地间均无显著性差异(P>0.05);黄秆乌哺鸡竹等8个刚竹属竹种至少有1个叶表型性状显著减小(P<0.05);福建茶秆竹、狭叶青苦竹有多个叶表型性状显著增大(P<0.05)。所有竹种叶质量的变异系数>20%,且青岛竹种叶质量的变异系数大于博爱,主成分分析也表明叶质量基本可以反映叶表型性状的全部信息。所有竹种的叶厚与温度因子显著正相关,与降雨量呈显著负相关(P<0.05),表现出了与环境相适应的变异特点。异速生长分析表明,12种竹子引至青岛后,叶厚与叶质量的生长速率增加,且叶质量的生长速率大于叶厚。研究结果表明,相比刚竹属竹种,福建茶秆竹与狭叶青苦竹对温度降低但降雨增加的青岛适应性更强,且叶质量是叶表型变异的主要因子,可作为竹类植物耐寒性的重要评价指标。

雷州山羊体尺与体重指标的主成分分析

目的:选育工作中以主成分为单位首先进行集团选择,再根据对主成分贡献率较大的单一性状进行筛选,以提高选育效率。根据雷州山羊体重和体尺性状之间的相关性进行主成分分析,可以为雷州山羊的选种提供重要参考依据。方法:该试验选取体重相近且健康状况良好的雷州山羊公羔60只,采用放牧+补饲方式饲养至60日龄断奶,并进行体重、体高、体斜长等11个体尺指的测定及主成分分析。结果:雷州山羊公羔的腰角宽变异系数最大,有较大的选择潜力;体重与管围的相关系数为0.484,达到显著正相关的水平(P<0.05)。体重与体尺性状可区分为相对独立的4个主成分:躯体因子、匀称因子、特征类因子以及宽度因子。第一主成分的贡献率为31.727%,其中胸深、额宽、体斜长以及肢高的特征向量系数较大,分别为0.432、0.413、0.384以及0.361。结论:胸深、额宽、体斜长以及肢高是雷州山羊公羔的主要性状指标。

乌原鲤形态性状与体质量的关系

为探究乌原鲤(Procypris mera Lin)形态性状与体质量的关系,采集广西水产科学研究院珍稀濒危鱼类繁育基地16月龄的乌原鲤142尾,4月龄乌原鲤83尾,测定其体质量(Y)、全长(X_(1))、体长(X_(2))、躯干长(X_(3))、体高(X_(4))、体宽(X_(5))、头长(X_(6))、头高(X_(7))、眼径(X_(8))、吻长(X_(9))、尾柄长(X_(10))和尾柄高(X_(11))共12个性状,利用相关性分析、通径分析和多元回归分析,筛选影响乌原鲤体质量的主要形态性状,并建立形态性状与体质量的多元回归方程。结果表明,16月龄乌原鲤各性状的变异系数均小于4月龄乌原鲤。通径分析表明,体高、体宽和眼径是影响16月龄乌原鲤体质量的主要形态性状;体高、体宽和头高是影响4月龄乌原鲤个体体质量的主要形态性状;但总决定系数均小于0.85,还需测量乌原鲤更多的形态性状指标。多元回归分析建立了16月龄乌原鲤形态性状与体质量的多元回归方程:Y_(A)=-14.891+1.548X5+0.887X_(4)-1.339X_(8);4月龄乌原鲤形态性状与体质量的多元回归方程:Y_(B)=-3.544+0.621X5+0.238X_(4)-0.137X_(7)。本研究丰富了乌原鲤的保护生物学数据,为乌原鲤分池培养提供了选择依据。

西洞庭湖洲滩植物物种与功能多样性空间分布特征及其相关性

洞庭湖是长江中下游重要的通江湖泊,具有调蓄洪水和维护周边湿地生态系统及生物多样性等生态功能。研究植物群落物种多样性与功能多样性在异质环境条件下的特征及其相关关系,对认识植物群落分布规律、保护修复生态系统结构和功能具有重要意义。以西洞庭湖沅江和澧水水流方向上的洲滩植物群落为研究对象,采集优势种并测定其根和叶的碳氮磷含量、叶面积和根长等8个功能性状来研究群落间物种多样性差异、水流方向上洲滩群落功能多样性差异、物种多样性和群落功能多样性的关系及多样性指数间的相关性。研究结果表明:(1)沿水流方向不同位置植物群落物种多样性有显著差异。其中,沅江和澧水的水流方向上入湖口物种丰富度均较低;在所有调查区域中,沅江中游洲滩植物群落物种丰富度、香农指数均较高,出湖口的物种多样性最低。(2)澧水上游洲滩植物群落的碳氮磷含量的群落加权平均值(community weighted-mean,CWM)和Rao二次熵指数较高;澧水中游植物群落所有性状的CWM值和Rao二次熵指数最低;沅江上游植物群落具有较高的叶性状值,优势种中一年生草本植物的快速生长策略可能贡献较高的叶性状值。(3)西洞庭湖洲滩植物群落物种多样性与CWM值具有显著相关性,根碳含量的CWM值与物种丰富度、香农指数呈负相关;水流方向上不同位置植物群落物种多样性与Rao二次熵指数没有相关性。研究结果说明,沅、澧两水及沿水流方向不同调查区域的水文地貌特征差异对洲滩湿地植物群落物种和功能多样性都有影响,但拥有更高物种多样性(优势种组成、丰富度等)的植物群落适应能力并不一定更强。此外,沿水流方向,湖泊洲滩植物群落的物种与功能多样性趋异。因此,在西洞庭湖洲滩植物群落的保护和修复工作中需要综合考虑更多因素(如土壤、地形等),以便更全面地了解其生态系统的复杂性和特殊性。

中华圆田螺形态性状对体质量的影响

为探究中华圆田螺(Cipangopaludina cathayensis)形态性状与体质量的关系,采集中华圆田螺共505只,并对其壳宽(Z_(1))、壳高(Z_(2))、壳口高(Z_(3))、壳口宽(Z_(4))、体螺层高(Z_(5))、螺旋部高(Z_(6))、倒数第二螺层宽(Z_(7))、倒数第二螺层高(Z_(8))和体质量(W)等9个体尺性状进行测量,通过统计分析、相关性分析、通径分析和回归分析,确定中华圆田螺对体质量影响较大的主要形态性状,并建立回归方程。结果显示,中华圆田螺体质量的变异系数为59.61%,其选育潜力较大;壳宽、壳高、体螺层高和倒数第二螺层宽与体质量的相关系数均较高(≥0.949)。通径分析和岭回归分析均表明,壳高对体质量直接作用最大(0.963,0.152),直接决定系数最高(0.927),其他性状与壳高对体质量的共同决定系数均较高,总决定系数达1.117。建立中华圆田螺体质量与各主要影响性状的最优多元回归方程:W=-24.346+0.214Z_(1)+0.148Z_(2)+0.123Z_(3)+0.306Z_(4)+0.188Z_(5)+0.083Z_(6)+0.383Z_(7)+0.882Z_(8),决定系数(R2)=0.943。回归方程的方差分析显示,其回归关系达到极显著水平(P<0.01)。综上,壳高是影响中华圆田螺体质量的最主要性状。

普通油茶良种资源表型性状多样性分析与综合评价

普通油茶(Camellia oleifera)是我国总产油量最高、栽培面积最广的木本油料作物。为促进我国普通油茶良种资源的挖掘与利用,本研究使用主成分分析、相关性分析、聚类分析、巢式方差分析、多元回归分析等方法以及变异系数、表型分化系数、香农-维纳多样性指数,探究560份普通油茶良种资源的表型性状多样性及其与环境因子的相关性,并使用熵权TOPSIS法对560份普通油茶良种资源进行综合评价和排序。结果表明,560份普通油茶良种资源存在丰富的遗传多样性,34个表型性状的香农-维纳多样性指数为0.05~2.35,均值为1.06,数量性状的变异系数为3.02%~53.33%,均值为23.25%。普通油茶良种资源34个表型性状种源间和种源内的方差分量均值分别为53.591%和32.382%,说明普通油茶良种资源表型性状种源内相似性较高,其分化主要来自种源间。随着纬度的升高和年平均温度的降低,普通油茶良种资源平均单果质量、种仁含油率及饱和脂肪酸含量呈现下降趋势,而不饱和脂肪酸含量呈现上升趋势,表明纬度和年平均温度是限制普通油茶生长的主要因子。熵权TOPSIS法综合评价和排序结果显示,长林4号综合得分指数最高,浙江、云南、安徽、湖南等地区均有多个选育的良种综合排名在前30以内。本研究结果为普通油茶育种及良种推广提供了数据支撑。

基于通径分析和灰色关联分析舟山近海中国鱚形态性状对体质量的影响

为了研究中国鱚(Sillago sinica)形态参数与体质量的关系,随机选取107尾舟山近海分布的中国鱚为研究对象,测量其体质量(X0)和11个形态性状:吻长(X1)、头长(X2)、体长(X3)、全长(X4)、尾柄长(X5)、尾柄高(X6)、体厚(X7)、眼径(X8)、眼间隔(X9)、眼后头长(X10)、体高(X11),并进行了相关性分析、多元回归分析、通径分析和灰色关联分析。测定的形态指标和体质量的相关性都达到了极显著水平(P<0.01),其中体长与体质量的相关性最大;剔除存在严重共线性的形态指标后,分别设置与体质量显著线性相关的体长和尾柄高为自变量、并将体质量设为因变量,构建了最优多元线性方程为Y=-87.734+6.174X3+24.398X6;通径分析结果显示,对体质量直接作用最大的为体长,间接作用最大的为尾柄高;灰色关联分析结果表明,与体质量的关联度排序靠前的5个形态参数分别为体长、全长、尾柄高、体高和头长。综合上述研究表明,中国鱚渔业资源的开发管理过程中应以体长为优先衡量指标、以尾柄高为辅助指标来制定最佳可捕规格和网目尺寸。