Spatial analysis increases efficiency of progeny testing of Chinese fir

We used spatial, global trend and post-blocking analysis to examine the effectiveness of a progeny trial in a tree breeding program for Chinese fir （Cunninghamia lanceolata （Lamb.） Hook） on a hilly site with an environmental gradient from hill top to bottom. Diameter at breast height （DBH） and tree height data had significant spatial auto-correlations among rows and columns. Adding a firstorder separable autoregressive term more effectively modelled the spatial variation than did the incomplete block （IB） model used for the experimental design. The spatial model also accounted for effects of experimental design factors and greatly reduced residual variances. The spatial analysis rel- ative to the IB analysis improved estimation of genetic parameters with the residual variance reduced 13 and 19% for DBH and tree height, respectively; heritability increased 35 and 51% for DBH and tree height, respectively; and genetic gain improved 3-5%. Fitting global trend and postblocking did not improve the analyses under IB model. The use of a spatial model or combined with a design model is recommended for forest genetic trials, particularly with global trend and local spatial variation of hilly sites.

Progeny Test on the Natural Populations and Selection of Excellent Populations from Fraxinus Mandshurica

Fraxinus mandshurica is one of the ancient relict flora species originated from the Tertiary period, which is mainly produced in the eastern mountains in Northeast China. It has an important scientific value for studying the Tertiary flora and the Quaternary glacial climate. In order to make rational use of the natural genetic resources of F. mandshurica , and to increase the scientific and technological added value of improved varieties, this study used the method of positional observation of fixed standard fields to discuss the genetic variations of tree height and DBH of the natural populations and its open-pollinated progenies, systematically analyze the heritability and genetic gains in growth characters based on the analysis of progeny test, growth dynamic and heredity effects. The populations with good growth, stress resistance and adaptability were selected. The results showed that there were extremely significant difference in the growth characters among the natural populations, and the coefficients of variance for tree height （22.99%） were smaller, while the coefficients of variance for DBH （41.37%） were larger. On the other hand, there were extremely significant differences in the growth characters among the open-pollinated progenies, and the interaction between these progenies and the blocks was significant. Meanwhile, the growth characters had strong heritability, high genetic gain, and remarkable heredity effects. The heritability of tree height and DBH were 0.825 and 0.781, and the genetic gains were 15.16% and 25.85%, respectively. Therefore, Shanhetun （SHT） and Xinglong （XIL） were determined to be excellent natural populations both in the growth, resistance and adaptation with growth traits as the main evaluation index, which could be widely applied in the advanced generation improvement breeding.

Theoretical analyses of testing efficiency in long-term breeding of poplar

The major goal for long-term poplar breeding can be formulated as maximizing annual progress in Group Merit Gain at a given annual budget （GMG/Y＊）. To evaluate different breeding scenarios, a deterministic simulator BREEDING CYCLE ANALYZER covering the most important aspects （gain, cost, time, technique, and gene diversity） of a full breeding cycle was used. The breeding strategies considered was based on pairwise crossing of the selected breeding population and balanced within family selection for the next breeding population. A main scenario and a number of alternative scenarios within these constraints were evaluated using estimates of the best available inputs for poplars. In focus was a comparison between three different testing scenarios for selecting the parents mated to create future breeding generations, thus selecting based on phenotype, clone test or progeny test. For the main scenario, the highest GMG/Y, and the optimal selection age for clone, phenotype and progeny strategies were 0.7480 %, 0.6989% and 0.4675%; 7, 6, and 11 years respectively. Clone test was best except when heritability was high, plant price was high or total budget was low; phenotype strategy was the second except for the case of extremely low narrow-sense heritability, for which the progeny strategy was a little more efficient than phenotype strategy. GMG/Y was markedly affected by narrow-sense heritability, additive variance at mature age, rotation age, plant-dependent cost, total budget and the time needed to produce the test plants, while diversity loss and recombination cost had rather weak effect on GMG/Y. Short rotation age and cheap testing cost favoured all three testing strategies. Comparably short rotation age, low plant-dependent cost and high total budget seem to promote early selection for progeny strategy.

Growth Performance of Cypress (Cupressus funebris) Trees in Progeny Test Plantations

Based on the 6-year-old young forests of 40 cypress(Cupressus funebris) families from four provenances(Fengdu County, Youyang County and Zhong County of Chongqing City, and Qiandao Lake in Zhejiang Province), differences in growth traits between families and provenances were studied to select excellent families, so as to provide necessary data support for the upgrading of cypress seed gardens and inferior thinning of seed gardens. The results showed that there were significant differences in tree height, diameter at one meter height, crown width and growth potential between families and provenances. The coefficients of variation among families were 10.25%, 7.19%, 5.91% and 0.98%, respectively, and the coefficients of variation in tree height and diameter at one meter height among provenances were 7.25% and 12.58%, respectively, indicating that the tree height and diameter at one meter height of the superior cypress tree families were rich in variation among families and provenances, and there was potential for high-generation breeding. According to the selection rate of 15%, six excellent families for afforestation(Feng 8, Shi 4, Feng 1, Ye 14, Shi 3, and Ye 6) were screened. The average diameter at one meter height, tree height and crown width of the six excellent families were, respectively, 2.97 cm, 3.39 and 0.78 m, which were 18.82%, 12.70% and 15.42% higher than the family average, respectively, and 15.09%, 9.79% and 15.53% higher than the control group, respectively.

Comparison, Selection and Progeny Test of Natural Populations of White Birch (Betula platyphylla Suk.) in Northern China

[Objectives]This study was conducted to rationally and effectively use natural genetic resources of white birch(Betula platyphylla Suk.),and improve the scientific and technological content of improved varieties.[Methods]With the progeny of the white birch populations naturally distributed in northern China as objects,based on genetic effect analysis and comprehensive evaluation,the genetic variation,heritability and genetic gain of the growth characters in the progeny forest were systematically analyzed,by which populations or individuals with good growth vigor and strong stress resistance and adaptability were finally selected.[Results]There were extremely significant differences in the growth characters between the natural populations of white birch in northern China.The variation was the smallest in tree height,followed by crown width,and largest in DBH,and the average coefficients of variation were 20.56%,32.25%and 33.00%,respectively.The differences in characters between progeny of the same population were also extremely significant.The growth characters of white birch were more controlled by genes,and the genetic gains were larger.The heritability of tree height,DBH and crown width was 0.971,0.816 and 0.576,respectively,and the genetic gains were 15.97%,21.54%and 13.87%,respectively.[Conclusions]With the growth characters as the main evaluation indexes,taking various influencing factors into account,the Shanxi[SX]population,Hebei[HB]population and Liaoning[LN]population were selected to be excellent populations,and LN305,SX516 and HB403 were excellent individuals,which are advised to be widely used in multi-generation genetic improvement breeding.

Validation of SSR Markers Linked to Flowering Time QTLs in Sorghum through Progeny Test

Flowering time is critically important for crop yield, and detection of its genetic factors with strongly associated DNA markers is necessary in breeding programs. This study was undertaken to validate the quantitative trait loci （QTLs） underlying flowering time of sorghum based on the association between genotypes at SSR marker loci and flowering time in F3 family lines from self-pollinated heterozygous F2 plants developed by crossing between ＂SC112＂---an early flowering variety from Ethiopia and ＂Kikuchi Zairai＂--a late flowering variety from Japan. The results showed that the SSR markers linked to the QTLs on sorghum chromosomes 1, 2, 3, 5b, 7 and 8b were significantly （P 〈 0.05） associated with flowering time, and these markers and the QTLs reported previously are valid. On the other hand, the genotypes at the marker locus SB596 of qFT1-2 on chromosome 1 was not significantly associated with flowering time. The valid DNA markers, SB258 in qFTI-1, SB 1512 in qFT2, SB 1839 in qFT3, SB3369 in qFT5b, SB4096 in qFT7 and SB4540 and SB4660 in qFT8b, might be useful for DNA-marker assisted breeding.

露水河沙松优良家系与优良单株初选

以吉林省露水河清水河林场17 a生沙松半同胞子代测定林为研究对象,测定81个参试家系(含1个对照)树高、胸径,调查成活率,估算遗传力,计算各指标变异系数、家系遗传力、遗传增益;采用综合评定法筛选优良家系与优良单株。结果表明:17 a生沙松平均树高为3.42 m,平均胸径为4.82 cm,平均材积为0.00533 m^(3)。参试家系各测定指标差异均达到极显著水平(P<0.01),家系间树高、胸径、材积和保存率平均变异系数分别为31.39%、51.75%、58.77%、24.02%;树高、胸径、材积家系遗传力和单株遗传力分别为0.545、0.593、0.572和0.232、0.284、0.260。经综合评分排序,按10%入选率筛选出77#、46#、103#、54#、5#、90#、7#、32#等8个优良家系,平均树高、胸径、材积分别为3.85 m、5.93 cm、0.00764 m^(3),分别比对照家系高0.39 m、0.95 cm、0.00184 m^(3),比总平均值高0.43 m、1.11 cm、0.00231 m^(3);优良家系树高、胸径、材积平均遗传增益分别为14.06%、35.33%、49.79%。在优良家系中按10%入选率选择优良单株18株,平均树高、胸径、材积分别为5.15 m、9.69 cm、0.02007 m^(3),分别比对照家系高1.69 m、4.71 cm、0.01427 m^(3),比总平均值高1.73 m、4.87 cm、0.0147 m^(3);优良单株树高、胸径、材积平均遗传增益分别为13.48%、24.69%、33.03%。选出的优良家系与优良单株可为吉林省沙松人工林培育提供育种资源。

罗田垂枝杉子代生长性状遗传变异及早期选择

罗田垂枝杉独特的形态特征使其成为林木理想的株型,具有较高经济利用价值和较大的推广应用前景,但其子代测定工作不够完善,各性状的遗传参数未知,这不利于垂枝杉的遗传改良工作。本研究分析杉木遗传变异规律,从而进行优良家系的早期选择,以期为垂枝杉种质资源的保护和选择育种提供理论依据。以罗田垂枝杉子代测定林为研究对象,比较分析不同家系间3年生、4年生林木树高、胸径的生长差异及其遗传规律,并展开优良家系的早期选择。结果显示:子代测定林3年生平均树高、胸径分别为3.11 m和4.07 cm,4年生平均树高、胸径分别为4.16 m和5.35 cm。各家系间生长性状在3年生和4年生时均存在极显著差异(P<0.01);表型变异系数为26.24%~41.83%,遗传变异系数为5.37%~9.15%,单株遗传力为0.3052~0.4318,家系遗传力为0.6099~0.7021,均受到中强程度的遗传控制。不同来源家系中,垂枝杉半同胞家系的生长性状均表现较好,且均为最大值。按照15%的入选率选出5个优良家系,分别为1-17、1-21、1-20、2-3和3-6,其入选均值分别为3.43 m(3年生树高)、4.74 cm(3年生胸径)、4.64 m(4年生树高)和6.20 cm(4年生胸径),平均遗传增益分别为6.71%、10.25%、7.92%和11.13%,选择效果明显,选育出的优良家系可以为垂枝杉种质资源的保护和选择育种提供极佳的种质材料。

杉木全同胞家系生长与木材基本密度性状的变异及选择

【目的】创制新优杉木种质材料,进而筛选速生优质家系,推进杉木高世代育种进程。【方法】以杉木第二代改良种子园10个骨干亲本作为杂交亲本,采用人工控制授粉方式获得30个全同胞家系,并进行多地点全同胞子代测定,分析其8年生杉木的生长和木材基本密度遗传变异规律,进而开展优良家系选择。【结果】家系间树高、胸径(DBH)、单株材积和木材基本密度(WBD)存在广泛遗传变异,差异达显著(P<0.05)或极显著水平(P<0.01),其中单株材积变异较大,各地点表型变异系数和遗传变异系数分别达到21.56%~28.53%、12.18%~19.64%。树高、胸径、单株材积和木材基本密度家系遗传力分别为0.1594、0.2232、0.1799和0.5357,有利于家系选择。利用BLUP方法估算全同胞家系亲本生长和木材基本密度育种值,同时按亲本模型估算各杂交组合的特殊配合力(SCA)并进行排名,综合生长性状和木材基本密度表现,选获速生优质型家系2个(家系5和29)。其中,家系5具有更高的生长和材质增益,相比群体均值其树高、胸径、单株材积及木材基本密度增益平均为6.02%、8.21%、15.82%、7.25%,而相比对照(2.5代种子园混合种)增益平均为26.47%、14.25%、34.56%、5.35%,因此,家系5是更理想的速生优质家系。【结论】30个杉木全同胞家系的生长和木材基本密度存在丰富的遗传变异,筛选获得的家系可作为候选杉木速生优质良种。

四川杉木2代种子园半同胞子代测定林生长性状的遗传变异分析

种子园子代测定林是开展推进种子园向升级换代的必要途径,对杉木第2代无性系种子园半同胞子代测定林13年生生长性状进行了遗传变异分析,以为杉木3代种子园的建设提供基础数据,结果表明:子代测定林的胸径、树高和材积在家系间、区组间以及二者的交互效应均存在显著差异,胸径和材积的家系遗传力为0.279和0.250,具有开展选优的价值和潜力;且胸径变异系数显示无论是在个体间还是在家系间生长都还在持续分化的过程中。51个家系胸径、树高和材积总的平均值分别为17.18 cm、12.61 m和0.1592 m3,相比对照均值现实增益分别为3.56%、2.66%和8.00%,材积现实增益超过10%的家系数量达21个,其中材积最大的家系现实增益达到了31.43%,现实增益明显。依据材积和胸径变异系数进行的综合优良度分析显示,T71,T78,T122,T152,T106,T114和T88等24个家系综合表现优异,可作为第3代无性系种子园建园材料的主要候选。

墨西哥柏种子园营建及早期选择

为提出结合子代测定建立种子园的方法和建立新一代种子园提供建园材料,对以种子园与子代测定相结合方式建立的滇中石林林场墨西哥柏实生种子园的102个优树子代,调查其10、20及26年生的墨西哥柏各生长指标,结合不同时期的疏伐进行相关分析和多阶段测定选择法开展选择研究。结果表明:种子园收集区26年生102个家系中保存了74个,保存率72.5%,50%以上的保存家系树高20 m以上,胸径25 cm以上,单株材积0.5 m3以上,四川3个种源间无显著差异,仅家系间差异显著;墨西哥柏在开始的3个10 a间,树高年均生长量呈“V”形变化,第1个10 a生长快,第2个10 a变缓,第3个10 a又变快,胸径和冠幅呈递减趋势,单株材积呈递增趋势;10年生时疏伐,疏伐后顶端优势降低,树高年生长量下降,20年生时疏伐,疏伐后树高年生长量升高,两次疏伐都促进材积年均生长量增长;比较10、20、26年生时的子代测定结果,10和20年生优良家系选择结果差异达44.4%,20和26年生优良家系选择结果仅有92号家系不同,其余家系在两次选择中均为优良家系,因此,10年生时进行早期选择尚早,20年生时的子代测定结果更准确,此时进行精英家系选择结果可靠。20年生时选出25个精英家系材积遗传增益为0.28%~19.02%,26年生时为优中选优,共选出62、71、59、83、87、67、53、90、76、70、95、69、92、60、99等15个精英家系可用于生产推广,材积遗传增益为0.15%~13.40%,考虑结实因素(枝下高为负增益),在此基础上选出59、83、87、90、76、95、92、99等8个家系作为种子园建园精英家系。结合子代测定建立墨西哥柏种子园的方法是可行的,采用初植密植,10年生时第1次疏伐进行家系内淘汰留存1株,20年生时再次疏伐,家系内和家系淘汰结合,可直接根据子代测定结果,将子代测定区和收集区的优良家系保留,去除不好的家系,改建为种子生产区,种子园正式建成。

不同种源红花香椿优树子代测定及早期评价

为掌握红花香椿(Toona fargesii)的生长特性与遗传变异规律,开展了优树子代测定试验,基于3种不同方法综合评价试验结果,筛选高遗传增益的优良家系推广利用,为红花香椿的选择和应用提供理论依据。结果显示:红花香椿自由授粉子代家系试验林2 a生时树高、地径和保存率均值为1.39 m、4.32 cm和89.0%,变异系数分别为29.1%、25.5%和16.0%;红花香椿家系试验林在树高和地径性状的区组间、家系间和家系×区组间差异都达到极显著水平,保存率在区组间和家系间差异达到极显著水平。红花香椿试验林的3个性状在家系水平上受到中等强度及以上的遗传控制(为0.44~0.79),采用聚类分析法、基因型分组法、BLUP育种值法3种方法进行对比选择分析,以25%的入选率初步筛选了3个红花香椿优良家系,可用于进一步育种研究。

火力楠优树子代测定与中期选择

本研究对火力楠(Michelia macclurei)11个家系的生长指标进行分析,估算其遗传参数与遗传增益。结果表明:子代测定林胸径、树高、单株材积和干形4个性状指标均值明显高于对照家系,通过多重比较入选3个家系,分别为23号、7号和5号家系,其遗传增益达23.3%、22.1%、10.5%和8.8%,可作为营建高世代的建园材料,也可用于优良材料的推广。

Inheritance of growth and survival in two 9-year-old, open-pollinated progenies of an advanced breeding population of Chinese firs in southeastern China

Tree growth traits （tree height, DBH and stem volume） and survival from two 9-year-old, open-pollinated progeny tests of Chinese fir were investigated for heri- tability, genotype × environment interaction, age-age genetic correlation and selection efficiency. The 97 and 79 families planted at two sites were collected from the thirdcycle seed orchard. Individual heritability was estimated between 0.05 and 0.21 for tree height, DBH, and volume and between 0.45 and 1.0 for survival. Family heritability was between 0.20 and 1.14. Significant genotype x envi- ronment interaction was observed for the three growth traits. Type B genetic correlation was between 0.41 and 0.67 with an increasing trend as tree grows. High age-age genetic correlation was observed with correlation reaching 0.9 after age 4 for height, DBH, and volume. The genetic gains were estimated at 3.26, 3.39 and 5.98 % for tree height, DBH, and volume with 10 % selection intensity. The implication for advanced tree breeding in Chinese fir is discussed.

思茅松半同胞和全同胞子代测定林生长性状遗传分析与选择

【目的】阐明思茅松生长性状的遗传变异规律和遗传控制程度,评价参试家系的生长表现,筛选优质的育种材料。【方法】以14年生思茅松半同胞子代测定林和6年生全同胞子代测定林为研究对象,对树高、胸径、材积3个生长性状进行遗传参数估算和性状相关性分析,并利用育种值和遗传值进行优良家系(组合)和优良单株选择。【结果】2类子代测定林3个生长性状的表型和遗传变异系数依次为材积>胸径>树高,生长性状间的遗传相关均达极显著水平(P <0.01);14年生半同胞子代测定林树高、胸径和材积性状的家系遗传力分别为0.680、0.691和0.748,单株遗传力分别为0.656、0.234和0.321,以材积为目标性状,根据参试家系育种值选出6个优良家系,其材积较对照提高37.9%~48.0%,入选优良家系材积的遗传增益为11.47%,按参试子代个体材积育种值选出52株优良单株,有78%的比例来源于优良家系,入选优良单株材积的遗传增益达30.64%;6年生全同胞子代测定林生长性状受中等强度的显性遗传效应影响,树高、胸径和材积的广义家系遗传力分别为0.245、0.256和0.204,根据遗传值选出2个优良组合,其材积遗传增益为15.53%。【结论】思茅松子测林材积性状的表型和遗传变异系数相对较高,适宜作为遗传选择的主要生长性状,基于遗传分析对思茅松子代测定林进行评价和选择能获得较好的遗传增益,可为思茅松的持续遗传改良选出较好的遗传材料。

5年生湿地松半同胞家系遗传变异和早期选择

为筛选适用于广西沿海地区树种结构调整的湿地松(Pinus elliottii)优良家系,以5年生湿地松子代测定林为研究对象,采用方差分析、遗传分析及增益估算,对生长性状进行评估,开展早期选择与评价。结果表明,20个参试家系间生长性状均差异极显著,变异丰富。19个参试家系的平均材积高于CK1,15个参试家系的平均材积高于CK2。参试家系的胸径、树高和材积遗传力分别为0.448、0.359和0.433,属中、高等遗传力。以材积为评选指标,初步选出4个优良家系,平均材积为0.0351 m^(3),比CK1高出31.0%,材积遗传增益为5.75%;湿地松15-524家系可作为广西沿海地区树种结构调整选择家系。采用综合法,初步选出14株优良单株,材积遗传增益为12.32%。

Comparison of genetic impact on growth and wood traits between seedlings and clones from the same plus trees of Pinus koraiensis

To evaluate the relationships among clones and open pollinated families from the same plus trees and to select elite breeding materials,growth,and wood characteristics of 33-year-old Pinus korainsis clones and families were measured and analyzed.The results show that growth and wood characters varied significantly.The variation due to clonal effects was higher than that of family effects.The ratio of genetic to phenotypic coefficient of variation of clones in growth and wood traits was above 90%,and the repeatability of these characteristics was more than 0.8,whereas the ratio of genetic to phenotypic coefficient of variation of families was above 90%.The broad-sense heritability of all characteristics exceeded 0.4,and the narrow-sense family heritability of growth traits was less than 0.3.Growth characteristics were positively correlated with each other,but most wood properties were weakly correlated in both clones and families.Fiber length and width were positively correlated between clones and families.Using the membership function method,eleven clones and four families were selected as superior material for improved diameter growth and wood production,and two families from clonal and open-pollinated trees showed consistently better performance.Generally,selection of the best clones is an effective alternative to deployment of families as the repeatability estimates from clonal trees were higher than narrow-sense heritability estimates from open pollinated families.The results provide valuable insight for improving P.koraiensis breeding programs and subsequent genetic improvement.

油松优树与子代生长性状的典型相关分析

该文以油松29个优树材料和其子代测定材料为研究对象,对油松优树的选优因子,包括树高、胸径和材积生长量大于优势对比木的百分比优树年生长量,与洛南、黄陵两个试点的子代测定林的生长因子的相关关系进行研究,并对子代林的生长性状进行遗传变异分析。结果表明:生长量大于优势对比木的百分比与洛南子代生长因子和黄陵子代材积性状无显著相关,与黄陵子代树高、胸径相关紧密;优树树高和材积年生长量与子代材积和胸径生长量相关显著。典型相关分析表明,生长量大于优势对比木的百分比对子代生长因子无显著相关作用,而优树生长因子中树高年生长量对子代胸径和材积起主要作用。按照5株优势木对比法选优测定结果,80%以上家系均大于对照,表明选优效果较好。

Pre-selecting young bulls before progeny-testing with marker-assisted BLUP

Suppose that a QTL affecting milk production trait of dairy cattle has been identified, and the relative dis-tances between the QTL and the markers are known without error. The relative efficiency of pre-selection of young bulls before progeny-testing with marker-assisted BLUP (MBLUP) over conventional progeny-testing (i.e. random selection be-fore progeny-testing) for five generations was studied using Monte Carlo simulation. Different numbers of QTL alleles (two or infinite), initial frequencies of the favorable QTL allele (0.1 and 0.5, when the QTL has two alleles), distances between the adjacent markers (5 cM or 20 cM), and ratios of the QTL variance to the genetic variance (10%, 25%, and 50%) were considered in the simulation. The results showed that the relative efficiency of MBLUP was higher when the marker distance was 5 cM than that when the distance was 20 cM. The larger the QTL allelic effect, the lower the MBLUP efficiency. The relative superiority of MBLUP was higher when the QTL had two alleles and the frequency of the favorable QTL allele was low in the base population. The relative superiority of MBLUP decreased with the pro-gress of generation in all cases and the decreasing rate was getting higher with the increase of marker density and QTL effect.

5年生马尾松实生种子园自由授粉家系遗传变异分析

对马尾松实生种子园自由授粉子代测定林5年生幼林的生长数据进行调查分析,研究马尾松实生种子园家系间的生长遗传变异。结果表明,家系间生长存在显著或极显著差异。以LSD多重比较生长差异达到极显著或显著且材积生长差异大于对照40%作为入选优良家系的条件,初选出25个优良家系,其平均材积、树高和胸径分别为0.02189 m^(3)、5.39 m和8.95 cm,分别比对照高52.01%、13.00%和20.30%,与对照平均值相比的遗传增益分别为5.36%、3.78%和10.49%,说明入选的优良家系增产效果明显,可为建设第2代种子园提供优质材料参考。