早中熟芋新品种鄂芋1号的选育

鄂芋1号是以走马羊红禾为亲本,通过单株选择法选育而成的芋新品种.早中熟,株高100～130 cm,叶片长50～56 cm,宽39～45 cm,叶柄紫黑色,叶片绿色;芋芽、芋肉白色,子孙芋卵圆形,整齐,棕毛少,单株母芋1个,单株子孙芋数25个左右,单个子芋质量50～70 g,单个孙芋质量32～42 g,单株子孙芋总质量1...     

Genetic consequences of low local tree densities - Implications for the management of naturally rare, insect pollinated species in temperate forests

Early on, researchers of evolutionary biology recognised that heterogeneity in the mating environment is an important source of variation in mating patterns. Focusing on the mating environment, we assessed the effect of conspecific tree density on mating patterns in the naturally scattered forest tree Sorbus domestica L. In an area of more than 100 km², we mapped and genotyped all 189 adult trees and performed a paternity analysis on seeds produced by single mothers. Despite a self-incompatibility system, average selfing rate was 31.9%, but with high variation among mother trees. Over 70% of this variation was explained by local density of conspecifics (i.e. within a radius of 300 m), with isolated trees being more prone to selfing. While we detected high selfing rates in progeny, adult trees showed no signs of inbreeding. As almost all inbreeding in the offspring could be attributed to self-fertilisation, we hypothesise that there is strong selection against selfed individuals. The effective reproductive output of isolated trees, which mainly self, is therefore greatly reduced. These findings have important consequences for the management of naturally scattered, insect-pollinated temperate tree species, often belonging to the family of Rosaceae. For these species, local density of conspecifics should be maintained above a certain threshold (i.e. 0.05 trees/ha in S. domestica), to avoid negative fitness consequences from selfing.     

家蚕育种数据管理系统的研制

利用VisualBasic 6 0forWindows开发设计了家蚕育种数据管理系统。该系统可以方便地制定育种计划 ,查询、管理、分析和比较育种数据 ,生成各种报表 ,同时可将 2台电子天平与计算机相连接 ,在实现对蚕茧个体、蛾区称量数据自动采集计算的同时 ,还能够根据个体称量结果自动对蚕茧做雌雄判别和个体选择 ,可有效提高育种效率。     

落叶松遗传改良的潜力

本文讨论了落叶松遗传改良的可能性及其潜力。其主要论点是:(1)落叶松(兴安落叶松、长白落叶松)种源间差异显著,种源遗传力较高;(2)落叶松个体选择效果明显.12～13年生的子代测定表明,家系间差异显著,遗传力很高,按家系选择可获得较大的遗传增益;(3)落叶松种间杂交优势明显、稳定,在F_2代申表现突出。     

A simulation of the development and restoration of old-growth structural features in northern hardwoods

Thinning treatments in second-growth forest may be a practical means of accelerating the development of certain old-growth structural features in regions where old stands are presently uncommon. We used CANOPY, an individual-tree model calibrated with data from thinned and unthinned stands, to simulate effects of thinning on growth rates and development of old-growth structural features in second-growth northern hardwoods. Three simulated, moderately heavy thinnings over a period of 45 years nearly doubled the predicted mean radial increment of canopy trees, percent of stand basal area in large trees, and area of canopy gaps. Compared to untreated stands, thinned stands had fewer dead trees per ha, but the dead trees were larger in size and the overall volume of snags and logs was little affected. In a 77-year old even-aged stand, moderately heavy thinning was predicted to reduce the time needed to attain the minimum structural features of an old-growth forest from 79 to 36 years. Simulated treatments in an older, uneven-aged stand gave mixed results; the moderately heavy treatment stimulated individual tree growth, but the removal of some medium-sized canopy trees in conjunction with natural mortality delayed the development of old-growth structure. Total volume of dead wood may still be deficient under the thinning regimes investigated in this study, but predicted live-tree structure 45 years after moderately heavy thinning was typical of stands in the advanced transition and steady-state stages of old-growth development. Results suggest that thinning can substantially accelerate the development of old-growth structure in pole and mature northern hardwoods, but response in older, uneven-aged stands is more modest, and treatments in these stands may need to be more conservative to achieve restoration goals.     

Basal area growth models for individual trees of Norway spruce, Scots pine, birch and other broadleaves in Norway

Distance-independent individual tree growth models based on about 30,000 observations from the National Forest Inventory and the Norwegian Forest Research Institute have been developed for the main tree species in Norway. The models predict 5-year basal area increment over bark for trees larger than 5 cm at breast height. Potential input variables were of four types: size of the tree, competition indices, site conditions, and stand variables including species, mixtures and layers. The squared correlation coefficient (R²) varied from 0.26 to 0.55. The accuracy of the models was tested by comparing the individual tree models with Norwegian diameter increment models. The accuracy is similar, but individual tree models forecast diameter distributions directly. The inclusion of species mixture and layer as variables increases the reliability of the models in mixed and in uneven-aged stands.     

红皮云杉优良家系内优良单株的选育技术

对19年生红皮云杉(Picea koraiensis)半同胞子代测定林(简称9501区)的苗高生长量分析表明,红皮云杉家系间存在丰富变异。52个家系差异极显著,选择26个为优良家系,其中4个为最优良家系。对这4个最优家系内单株分析表明,单株变异较大;其中,M185高生长最大的单株是490cm,最小的单株是270cm,相差1.82倍;M180高生长最大的单株是470cm,最小的单株是240cm,相差1.96倍;M9112高生长最大的单株是421cm,最小的单株是250cm,相差1.68倍;N10高生长最大的单株是450cm,最小的单株是80cm,相差5.63倍,家系内单株差异极显著,是建立第二代种子园候选家系。     

Construction of the Effect Evaluation System of Rural Citizens＇ Information Literacy Education

农村公民信息培训效果评估体系包括个体评估和整体评估两部分。个体评估部分由3个维度11个二级指标构成。具体评估由调查问卷、试题、论坛使用3个部分组成。整体评估部分由听课记录卡分析、相关因素一致性比对分析与调查问卷统计分析两部分组成。     

苏啤3号基本苗对群个体质量及产量的影响

为了研究不同播种密度的基本苗对苏啤3号群个体质量与产量的影响。设120万1、80万2、40万3、00万和360万/hm25个播种密度基本苗处理,通过田间试验研究基本苗与不同生育时期总苗数、单株分蘖(成穗)数、叶龄、株高、次生根条数、干物质积累量、抽穗期单茎叶面积、叶面积系数和粒叶比以及产量及其构成因素的相关性。随基本苗的增加,不同生育时期的总苗数和有效穗数增加,单株分蘖(成穗)、次生根数、单株干物质积累量、单穗粒数、千粒重等不断减少,叶龄、株高变化不明显。个体与群体有相互补充作用,当个体弱而群体强或群体强而个体弱时,都可能取得理想产量。综合考虑,基本苗为270万/hm2时,对江苏里下河地区的啤麦生产最有利。     

灰色系统理论在豇豆育种中的应用研究

本文将灰色系统理论应用于豇豆亲本分类、育种目标性状选择、杂交组合评判、单株选择、品系比较等育种实践之中,成功地选育出豇豆新品种“早翠豇豆”和16×6－20－3等优良品系。