核桃茎段组织培养

选用汾阳核桃实生苗和核桃20年生树为试材,利用L9（3^4）正交来对影响核桃茎段组织培养中腋芽分化的3种主要激素种类的浓度进行设计,试验中发现取材于20年生核桃树的外植体茎段和叶片污染、褐变现象严重,苗分化数以及愈伤组织分化数达不到统计样本要求。故试验结果均是以核桃实生苗茎段为外植体材料得到的。诱导芽分化和增殖的培养基均为改良DKW。试验结果显示：核桃茎段腋芽萌发的最佳激素组合为BA0．5mg／L＋KT0．5mg／L＋IBA0．02mg／L。     

Genetic variation for carbon isotope composition in honey mesquite (Prosopis glandulosa)

Carbon isotope composition (delta(13)C) is a useful surrogate for integrated, plant water-use efficiency (WUE) when measured on plants grown in a common environment. In a variety of species, genetic variation in delta(13)C has been linked to the distribution of genotypes across gradients in atmospheric and soil water. We examined genetic variation for delta(13)C in seedlings of honey mesquite (Prosopis glandulosa Torr.), an invasive grassland shrub that thrives in the southwestern USA. Fifteen maternal families, representing progeny of 15 adult trees, were studied in three common garden experiments in a greenhouse. The 990-km east-west transect along which the adult trees were located encompasses a wide precipitation gradient, and includes mesic grassland, semiarid grassland, and Chihuahuan desert ecosystems. Genetic variation for delta(13)C in mesquite was substantial, with the rank order of half-sib families based on delta(13)C relatively stable across experiments, which were conducted under different environmental conditions. Conversely, rankings of families by mean seedling height (an index of growth rate) varied markedly among experiments. Seedlings derived from Chihuahuan desert adults emerged more quickly and had more negative delta(13)C (indicative of lower WUE) than seedlings derived from the other regions. Although delta(13)C and seedling height were not correlated, these results suggest that mesquite genotypes at the drier, western extreme of the species' range are adapted for quicker emergence and possibly faster growth than genotypes from mesic areas. Together, these traits may facilitate exploitation of infrequent precipitation events.     

核桃栽培存在的问题与对策探讨

为解决核桃栽培管理方面的问题,笔者采用全面普查和典型调查方法,对十堰市核桃分布及栽培情况进行调查分析,提出了十堰核桃生产中目前存在的粗放管理、病虫害、过早采摘等5个主要问题,并相应提出了解决办法和对策。为提高核桃栽培水平,促进核桃产业化进程进行了初步探讨。     

核桃实生群体物候的观测

为给核桃抗晚霜品种的选育和晚花性状的分子辅助选择研究奠定基础,对泰安地区核桃F1实生群体的物候期进行了连续4年的观测。结果表明:核桃实生群体从3月中下旬开始萌动,3月下旬进入萌芽期,4月初至5月初随着叶片展开、新梢生长,混合芽中的雌花及枝条上的裸芽雄花陆续开放,8月下旬至10月初果实成熟,10月中下旬至11月上旬进入落叶期;核桃的物候特征是不同单株固有的遗传特性,不同年份其物候期不尽一致,但各单株上出现的先后次序是相对稳定的,而且,核桃实生群体中不同单株间的各物候时期的变异系数较高,这为晚花抗晚霜优良单株的选择提供了丰富材料。     

宜昌市核桃产业发展现状、问题及对策

核桃在湖北省宜昌市栽培历史悠久,是营养价值很高的木本油料果树。笔者就宜昌市核桃产业发展现状、问题及对策谈了几点看法,供同仁参考。     

核桃嫁接方法与时期试验研究

在多年发展核桃产业中,笔者对核桃嫁接繁育的合适时机及方法,进行了反复试验和生产应用。结果表明:在鄂西北地区,从2～8月期间约有5个月时间皆可进行嫁接育苗。早春(2～3月)宜室内温控双舌对接;6～8月可圃地芽接和林地高位芽接。大量快速繁育优质核桃苗宜在6～7月间采用圃地芽接。     

核桃高效采穗圃系统修剪技术研究Ⅲ核桃高效采穗圃经济效益分析

建设核桃高效采穗圃，在8a经营期内，投资回收期短、净现值比值高、内部收益率大于50%、投资净现值比值高、经济效益显著。     

兴山县核桃产业现状及其发展对策

笔者在对兴山县的核桃资源分布、发展现状进行调查分析的基础上,指出了该县核桃产业发展存在的主要问题,提出了核桃产业升级的主要对策及发展方向.     

恩施州核桃生产现状与发展对策

笔者在调查恩施州发展核桃产业的现状的基础上,分析了发展核桃产业的优势,并提出了发展核桃产业的思路与对策,供同仁参考。     

湖北核桃良种培育研究初报

摘要：笔者从1999年开始湖北核桃资源调查,初选出50棵优株,经复选、决选、品比试验等。在鄂西南、鄂西北等主产区进行区试,试验与扩大生产示范结合,连续多年多点对其植物学特征、生物学特性、果实经济性状、抗病抗逆性等进行系统观察分析。结果表明：选出的优株EH9909其丰产性、坚果品质、抗核桃褐斑病、核桃细菌型黑斑病能力明显优于湖北省兴山普通核桃。     

鄂西地区核桃良种引种筛选初报

良种的调查筛选是林木引种驯化的一项重要的前期基础工作,笔者调查了北方核桃产区7 a生早实核桃品种(无性系)18个在鄂西地区栽培的抗病能力,调查了南方核桃产区10个核桃品种在鄂西地区栽培的抗寒能力,综合比较鄂西地区与国内核桃产区的气候条件,确定云南、河北、山东、辽宁核桃产区的辽宁一号、鲁光、香玲、元丰、中林、云杂系列品种为鄂西地区区域化试验的试验材料。建议开展不同品种在鄂西地区适生区域选择的系统研究。     

湖北核桃良种培育研究初报

笔者从1999年开始湖北核桃资源调查,初选出50棵优株,经复选、决选、品比试验等。在鄂西南、鄂西北等主产区进行区试,试验与扩大生产示范结合,连续多年多点对其植物学特征、生物学特性、果实经济性状、抗病抗逆性等进行系统观察分析。结果表明:选出的优株EH9909其丰产性、坚果品质、抗核桃褐斑病、核桃细菌型黑斑病能力明显优于湖北省兴山普通核桃。     

发展核桃特色产业推进现代林业建设

笔者阐述了保康县核桃产业发展的现状与发展中存在的问题,分析了问题存在的原因,并从林业产业化的角度提出了发展核桃产业的建议与对策。     

南北核桃种间杂交F1代主要性状遗传分析

1979～1997年首次选用南方云南薄壳核桃与北方新疆核桃早实优株进行了18个杂交组合的南北核桃种群杂交.对杂种F1代7个主要性状的遗传分析表明杂种F1代的主要性状广泛复杂分离,为多基因控制呈数量性状遗传.由于基因的加性效应,F1代可组合双亲优异性状,由于基因互作产生非加性效应,F1代产生杂种优势性状.这些遗传趋势和特点,对核桃的进一步育种工作有重要的指导作用;也为下一步的育种提供了优良材料.     

早实核桃产量影响因子研究初报

在对68株8a生核桃树体结实产量及其相关影响因子的数量分析基础上,求得产量及各因子的变异系数、简单相关系数,并通过多元回归分析,确定影响核桃产量的主要因子。     

核桃的几种典型生态结构模式综合效益分析评价

笔者根据有利于核桃的立体种植中上下层植物生长,产生良好的生态、经济社会效益为原则,采用双效互补、增加植被覆盖率与土壤养分、涵养水源的生态经济林模式造林并进行高效栽培管理,能充分利用光和热,较之单一的核桃或经济作物种植,能实现生态持续和经济持续的有机结合,达到产品多样化、高产出的目的。     

西藏核桃研究进展及发展趋势

在综述西藏核桃的起源、分布、坚果特性、遗传多样性及引种栽培等方面的研究进展的基础上,结合西藏核桃发展需求,探讨西藏核桃的发展趋势,可为西藏核桃产业的可持续发展和进一步的研究工作提供参考。     

Intrapopulation variation in flowering phenology and fecundity of silver birch, implications for adaptability to changing climate

Earlier modeling has suggested that long distance gene flow is of importance in increasing the adaptability of tree populations in a changing climate. In times of warming temperatures, early flowering phenotypes may be favored, because early flowering may be connected to early onset of growth. Long term direct measurements of flowering, pollen cloud and intrapopulation fecundity variations are needed to test this hypothesis. Having one of the furthest transported types of pollen grains, birch may have good potential for long distance gene flow. Our daily observations over eight years, of 30 silver birches (Betula pendula Roth), showed that the onset and duration of flowering phenology was determined by the accumulation of spring temperature sums, but the window for potential long distance gene flow was narrow. The interannual phenology variations were large, the order of timing of female and male catkins in various trees of this monoecious species tended to differ, and the timing of generative and vegetative spring phenologies were not correlated at tree level. Early flowering trees tended to have a higher variation in germinability than later flowering trees. No other connection between timing of phenology of flowering and seed quantity or quality was found. Although stochastic climatic conditions produce interannually variable phenological windows, probability for long distance gene flow from areas differing in timing of spring temperature accumulations may be low in silver birch. Intertree variations in fecundity were high, and the majority of seeds and pollen were produced by only a few trees. Moreover, the amount of seeds produced was positively related to seed germinability, thus large phenotypic fecundity variations may decrease interannual genetic variations in seed sets.     

核桃芽接接穗生理成熟的植物学形态特征

植物芽的生理成熟是对植物嫁接的基础,核桃生长期嫁接均采用半木质化为指标。以‘云新’7个早实核桃品种为对象,采用对生长期方块芽接不同芽位的植物学特征观察,归纳核桃半木质化枝条生理成熟的植物学形态特征。通过生产检验结果表明,适宜作生产方块芽嫁接接穗的植物学形态特征是：枝条接穗段圆形;表皮颜色达到品种成熟枝条的色度,如灰白、深灰、灰绿色;表皮无毛.