广东城市土地集约利用评价及其时空变异分析

采用层次分析法构建城市土地集约利用评价模利与评价指标体系,对广东21个地级市城市土地集约利用状况进行综合评价.运用Spearman秩相关系数、协调度分析法、聚类及GIS分析法,对评价结果的时空变异规律进行分析.结果表明:(1)在1999-2008年广东大部份城市土地集约利用水平得到不同程度的提高,如东莞、河源等,而阳江、茂名等8个地区则出现下降趋势,江门和汕头下降最为显著.(2)城市土地集约利用综合指数与协凋度相关性不强.进行城市土地集约利用评价时,应综合考虑综合指数与各要素层之间协调度的问题.(3)广东城市土地集约利用水平具有明显的空间分异规律,珠江三角洲地区城市土地集约利用综合指数高于粤北山区及东西两翼.     

使用SPSS软件进行多因素方差分析

以两因素完全随机有重复的试验为例,阐述用SPSS软进行方差分析的详细过程,包括数据的输入、变异来源的分析,方差分析结果,以及显著性检验,最后还对方差分析注意事项进行分析,为科技工作者使用SPSS软进方差分析提供参考。     

结缕草高频再生体系的建立和优化

以结缕草叶片为外植体进行离体再生研究.结果表明:叶片愈伤组织诱导的最佳培养基是 MS+1.5 mg·L-1 2,4-二氯苯氧乙酸(2,4-D)+0.5 mg·L-1 6-苄基腺嘌呤(6-BA)+26 g·L-1 蔗糖+5.0 g·L-1 琼脂,诱导率为 65.36%,无性世代增殖倍数高达 9.56;正交试验和方差分析筛选出不定芽分化最佳培养基为 MS+3.0 mg·L-1 6-BA + 0.5 mg · L-1 萘乙酸(NAA) +1.5 mg·L-1 AgNO3+35 g·L-1 蔗糖+6.5 g·L-1 琼脂,分化率为 67.30%,增殖系数为 8.67;生根培养基选用 1/4 MS+0.2 mg·L-1 吲哚丁酸(IBA)+0.3 mg·L-1 NAA+28 g·L-1 蔗糖+4.5 g·L-1 琼脂,生根率为 90.00%.     

杉木木材基本密度变异的研究

利用设置在分布区北缘江苏宁镇丘陵（句容、江宁）的各种试验测定林所收集的２４个种源、５０个江苏当地种源优树半同胞子代、１７个产地间杂交组合子代４９０株平均木选择材料,以及融水种源山洼、山谷、山坡３种栽植立地,３０００、４９５０、６０００株·ｈｍ－２３种栽植密度,以及６、８、１０、１５、１８ａ等５个年龄组林分２７５株样木材料研究杉木木材的基本密度变异规律。结果表明,杉木全分布区试验不同种源,江苏种源优树自由受粉子代家系,江苏江宁×四川德昌种源产地杂交组合子代间有显著的遗传变异（依次为：Ｆ＝６．７１＊＊＞Ｆ０．０１＝２．４０;Ｆ＝３．８７＊＊＞Ｆ０．０１＝２．１９;Ｆ＝２．６３＊＞Ｆ０．０５＝２．３６）,具有选择改良潜力。栽植立地对融水种源幼龄材基本密度没有明显影响;林龄与栽植密度是引起木材基本密度变异的重要因素。供试测定材料基本密度与材积生长没有统计置信的负相关关系,性状间影响弱。杉木材性改良及生长与材性联合改良,可按“生长（材积）、材性（基本密度）两阶段独立选择法”进行改良。     

Linear relationships between agronomic and nutritional traits in transgenic genotypes of maize

The aims of this study were to assess the linear relationships between agronomic and nutritional traits and identify promising traits for indirect selection in transgenic genotypes of maize. Eighteen transgenic maize genotypes were assessed in randomized blocks with three replications. The agronomic (number of days from sowing until male flowering, number of days from sowing until female flowering, plant height, ear insertion height and grain yield) and nutritional (crude protein, ether extract, crude fiber, starch and amylose) traits were measured. Analysis of variance was run for each of the 10 traits and phenotypic and genotypic correlation coefficient matrices estimated. Ridge path analysis were performed the nutritional traits were treated as main variable (dependent) and agronomic traits as explanatory variables (independents). The number of days from sowing until female flowering has a positive linear relationship to crude protein, ether extract and starch. Plant height has a positive linear relationship to crude fiber. Ear height has a positive linear relationship to amylose. Grain yield has a positive linear relationship to starch. The number of days from sowing until male flowering, plant height, ear height and grain yield can be used indirect selection in maize.     

黄土丘陵区退耕地景观植被与土壤特征时空变异及其相关分析

对黄土丘陵区退耕地景观不同尺度的植被特征中的物种丰富度、物种多样性、物种均匀度,土壤特征中的有机质、全N和全P含量的相关关系和时空格局进行了研究。结果表明:区域尺度退耕地的植被指数小于流域尺度,但具有更大的变异性。两种尺度上物种丰富度与物种均匀度之间、物种多样性与物种均匀度之间均存在接近显著或具有显著的正相关关系,有机质含量与全N含量之间存在着极显著的正相关关系。区域尺度和流域尺度退耕地的植被特征与土壤养分含量具有不同的时空格局,但并没有显著的相关关系。说明黄土丘陵区退耕地植被特征和土壤养分含量可能受控于别的环境因素或干扰过程,导致了其植被特征与土壤养分特征的时空差异性。     

Dissection of additive genetic variability for quantitative traits in chickens using SNP markers

The aim of this study was to separate marked additive genetic variability for three quantitative traits in chickens into components associated with classes of minor allele frequency (MAF), individual chromosomes and marker density using the genomewide complex trait analysis (GCTA) approach. Data were from 1351 chickens measured for body weight (BW), ultrasound of breast muscle (BM) and hen house egg production (HHP), each bird with 354 364 SNP genotypes. Estimates of variance components show that SNPs on commercially available genotyping chips marked a large amount of genetic variability for all three traits. The estimated proportion of total variation tagged by all autosomal SNPs was 0.30 (SE 0.04) for BW, 0.33 (SE 0.04) for BM, and 0.19 (SE 0.05) for HHP. We found that a substantial proportion of this variation was explained by low frequency variants (MAF <0.20) for BW and BM, and variants with MAF 0.10–0.30 for HHP. The marked genetic variance explained by each chromosome was linearly related to its length (R² = 0.60) for BW and BM. However, for HHP, there was no linear relationship between estimates of variance and length of the chromosome (R² = 0.01). Our results suggest that the contribution of SNPs to marked additive genetic variability is dependent on the allele frequency spectrum. For the sample of birds analysed, it was found that increasing marker density beyond 100K SNPs did not capture additional additive genetic variance.     

Gene effects for cotton-fiber traits in cotton plant (Gossypium hirsutum L.) under Verticillium conditions

Verticillium wilt (VW), caused by Verticillium dahliae Kleb., has become one of the most serious problems in cotton (Gossypium hirsutum L.). The use of resistant cultivars has long been considered the most practical and effective means of control. The objective of this work was to study the quantitative genetic basis of fiber traits under Verticillium conditions in upland cotton by using five genotypes and their possible crosses without reciprocals, selecting simultaneously for quality fiber, resistance, and agronomic characteristics. Five cotton cultivars and 10 F₁s from half diallel crosses were analyzed for quality fiber under VW conditions. The fiber length, uniformity, strength, elongation, and micronaire were measured during two crop seasons at two different sites each year, consistently in plots with soil naturally infested with Verticillium. Genetic components of variance were analyzed using the Hayman model. Analysis of variance for all traits showed significant differences between genotypes, with the genotype–site interaction in most of the studied traits except for fiber length and micronaire. Both the additive genetic variance component (D) and dominance genetic variance components (H1 and H2) were present in all traits. D was the most important component for uniformity, strength, elongation, and micronaire. Elongation was the trait most correlated with seed-cotton yield. Strength and micronaire were the traits most correlated with VWI. Broad-sense heritability was high for all the traits studied. Narrow-sense heritability was high for uniformity, strength and elongation, and moderate for length and micronaire.     

水稻成熟胚离体培养有关性状的遗传分析

采用p(p+1)／2半完全双列杂交与f×m 不完全双列杂交法,研究了两个水稻群体成熟胚离体培养的遗传表现。结果表明,水稻成熟胚愈伤组织诱导率和绿苗分化率的高低主要受亲本基因型的影响,即基因型不同,差异很大,不仅存在基因的加性效应,也表现出非等位基因的互作效应,遗传表现为部分显性,其遗传模型为加性一显性一上位性模型,遗传力较低,而成熟胚的离体培养力的遗传模型为加性一显性模型,具较高的遗传力。     

国外引进甘蔗品种综合分析

采用灰色多维综合隶属度评估分析和方差分析两种方法,对10个国外引进品种进行综合分析。结果表明:Q141、Q170、SP80-1842、RB76-5418和CP85-1308五个品种生势强,丰产性能较好,综合性状好,可考虑进一步对其进行区域性试验、繁殖、示范、推广;RK88-188、67N3184、Laica82-1729、Mex73-206和FR94-444五个品种性状表现有缺陷,需进一步试验观察或作为亲本材料保存利用。