共查询到18条相似文献，搜索用时 453 毫秒
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为探讨火炬松(Pinus taeda)无性系花粉产量的变异,在火炬松1.5代种子园选出20个无性系,每无性系5株,共100株火炬松作为研究材料,调查胸径、树高、冠幅和花粉量,通过对比单株花粉量、单位面积花粉量和单位面积有效花粉量来筛选高花粉产量的无性系.结果表明,单株花粉量与冠幅呈显著正相关(P<0.05),单株花粉量最高的是243无性系,为1302.55 g;单位面积花粉产量最高的是201无性系,为36.70 g/m2;单位面积有效花粉量最高的是243无性系,为34.14 g/m2;花粉活力最大的是298无性系,为100%.火炬松种子园的花粉产量变异主要来源于无性系间,最终筛选出243、201和298无性系3个优良无性系. 相似文献
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对油茶闽杂优等12个无性系在闽中德化山区的5年生幼树生长和结实情况进行了调查分析,结果表明:油茶闽杂优30、闽48、闽杂优20、闽杂优5、闽杂优25等5个无性系产量高,5年生平均树高1.28~1.73m,地径3.32~5.10cm,冠幅乘积0.87~1.44m^2;平均单株产果3.31~1.60kg,单株产油0.34~0.153kg,鲜果含油率达10.27%~6.02%;其中闽杂优20树体较矮小,冠幅窄。方差分析表明各无性系间生长结实有显著差异,因此闽杂优30、闽48、闽杂优20、闽杂优5、闽杂优25等5个无性系是目前幼林中的优良无性系,在德化海拔850m的山区表现出早结实、产量高、生长较快的特点。 相似文献
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调查观测了油茶闽优10个无性系在闽东山地的生长结实状况,结果表明:油茶闽优不同无性系在树体生长和鲜果产量方面差异显著。闽54、闽62的树高生长快,闽49、闽56、闽54的地径生长粗,闽56的冠幅生长最大,闽48的树高、地径、冠幅生长慢;油茶良种闽43、闽60的产果量高,适合在闽东地区推广种植。 相似文献
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研究油茶赣8无性系在不同坡向、坡度、立地质量条件下,采用同样经营措施,对其产果量的影响。结果表明,各个单株产量和生长量差存在极显著差异,说明同一个油茶赣8无性系其营养和生殖生长差异受气候、土壤、坡向、立地质量等因子影响较大,提高单位面积产量关键是选择优良单株和通过合理修剪培育高光效的树冠。 相似文献
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为了能在较短时间内筛选出适于广东栽培的油茶良种,从江西、湖南、广西等省区引进普通油茶优良无性系,2007年在广东连州开展田间试验。结果表明:参试各无性系平均单株结果量间的差异显著,各无性系单株结果量的重复力为0.595 1;初步选择出江15、桂A、101、桂3、江11、105这6个优良无性系,其平均单株结果量为74.33个,试验林平均单株结果量为56.26个,无性系选择遗传增益为19.11%;通过分析试验林的单株产量结构可知,结果量达一、二等的单株占参试所有无性系群体的比重不高,仅分别占4.8%、7.5%。 相似文献
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橄榄优良品系扩大试验 总被引：3，自引：3，他引：0
在高州市大坡镇、古丁镇以及茂名市八一林场三个试点开展橄榄优良品系嫁接扩大试验,嫁接后第3,4年的结实及生长结果如下：（1）无性系间单株产果量、单位树冠投影面积产果量均达极显著差异水平,树高、径粗和冠幅在有的试点达极显著差异、有的试点无显著差异,表明无性系间结实存在着遗传差异,通过无性系测定选择的高产无性系有效。（2）对单株产果量、单位树冠投影面积产果量的多重比较结果,3个试点一致表现为G18无性系的两项结实指标值均显著高于其他参试无性系,进一步证明G18是一个真正优秀的高产无性系,对立地变化有很强的适应性。大树换接的平均单株产果量达15．04kg,一年生砧木嫁接达2．30～9．10kg。（3）橄榄无性系结实的广义遗传力很高,达0．961～0．969;当选择率为0．1时,结实遗传增益达16．36％～68．25％,入选率为0．11～0．14时,结实现实增益达59．36％～108．74％。（4）G18无性系结实的主效（Gi）在各试点均明显高于其他参试无性系,达0．4250～0．7176,其无性系与年份互作效应（δ^2cw）小,互作效应方差的变异系数（iCVCW）为0～5．89％,表明G18无性系的丰产性极佳且稳产性好,对年份间的气候条件变化有较强的适应性。 相似文献
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Differences in stem wood production were found among four clones of Picea sitchensis (Bong.) Carr. at both an agricultural and a forest site. Clonal rankings were not consistent between the sites. Four variables were identified that may influence stem wood production, foliage amount, total aboveground production per unit foliage, proportional allocation of production to new foliage and to branch wood thickening. Comparison of clonal performance between sites showed that stem wood production could be influenced by differences in each of these variables. The four variables were themselves determined by components of crown structure, these were (i) production of new branches from the main stem, (ii) the numbers and lengths of branchlets supported on branches from the main stem, (iii) foliage production per unit branchlet length and foliage longevity, and (iv) branch wood thickening per unit branch length. These components varied both among clones and between sites. Branch production from the mainstem varied among clones, and for some clones it varied substantially between sites. In some clones branch production was positively correlated with mainstem height increment. There were differences among clones in the way that branchlet production varied between the agricultural and forest sites. In the absence of needle fall, foliage weight/branch length varied threefold among clones, but for each clone, varied little between sites. Branch wood weight/branch length was generally greater when foliage weight/branch length was large, but total branch wood increment/tree was strongly influenced by total branch length. The dynamics of crown development and its relation to stem wood production are discussed with reference to (i) the importance of needle longevity, (ii) the importance of tallness and narrowness of crowns and (iii) the importance of branch thickening, a process that competes with stem growth in the utilization of photosynthate. It is concluded that although each of these factors may be important, none singly accounts for the observed differences in stem wood production among genotypes and the way these change in response to the environment. 相似文献
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油茶高油份高产量新品种选育研究 总被引：8，自引：2，他引：8
湖北省油茶双高课题组 《湖北林业科技》1996,(3):24-30
该研究采用边测定、边示范、边推广的技术路线，对经过连续１０年测产的１０个优株，采用芽苗砧嫁接无性繁殖苗木营造测定林，进行多点多重复区域化试验，选育出五油１５１、五油１０２、五油４６５等高产量、高含油率的新品种。新选出的优良品种平均产油４５０ｋｇ／ｈａ以上，比参试无性系均值高１５％以上，每ｍ￣２冠幅产油量比１９８５年国家制定的标准高２３．０～１０４．０％。同时，采用选育的优良品种营建采稳固１６．３３ｈａ和试验示范林６６６．６７ｈａ，取得了明显的效益。 相似文献
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Basal shoots of five clones of mature chestnut tree (Castanea sativa Mill. and C. sativa x C. crenata Siebold & Zucc.) had a greater capacity for in vitro establishment, multiplication and rooting than crown branches of the same trees. Cultures from basal shoots were more responsive than crown-derived cultures in terms of in vitro reactivity (proportion of the explants with shoot development), the mean number of shoots formed per explant, the length of the tallest shoot in each culture, and the multiplication coefficient (defined as the product of the reactivity and the mean number of shoots per explant). Multiplication coefficients were greatest between subcultures 6 and 12, but subculturing failed to increase the rooting potential of shoots of crown origin. Multiplication and rooting rates were also determined for clones derived from seeds of mature trees. Genotype influenced the in vitro performance of clones of both adult and seedling origins. 相似文献
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对湖南省东安县杉木无性系种子园母树的生长结实性状进行定点观察和综合分析，结果表明，不同地理种源球果产量的差异，均未达到统计上的显著水平．但在不同无性系间，存在显著的差异：树高和胸经在种源和无性系间均存在显著差异，冠幅仅在无性系间有差异，枝下高差异不明显；树高、冠幅与球果呈极显著相关．胸经与球果呈显著相关，枝下高与球果相关不明显．偏北种源较偏南种源球果产量高．种源和无性系的球果重复力偏低．据此，对种子园的营建和经营管理，提出了有益的建议和讨论 相似文献