影响番茄离体培养再生的主要因素探讨

以5个番茄品种的子叶和下胚轴为外植体,对无菌苗的生理状态、激素组合、激素浓度和基因型等影响组培效果的主要因素进行探讨,建立了番茄的高效离体培养再生体系。结果表明,下胚轴和子叶均得到了高达100%的出愈率和95%以上的分化率;最佳的品种是T431;最佳激素组合为ZT1.0mg·L-1和IAA1.0mg·L-1。     

次生幼龄林封山育林后乔木层物种结构变化研究

1999年在浙江省仙居县俞坑村的封山育林区设置20 m×20 m的固定样地2块,对连续5年的调查数据进行统计分析,以其对次生幼林乔木物种结构变化进行研究.分析结果,乔木层物种丰富度指数增加了7～11,乔木物种增加了2～5科,3～8属.自然恢复为以壳斗科、杉科、山茶科、樟科、胡桃科、安息香科等物种为建群种或共建种的次生常绿阔叶林、针阔混交林.     

德国核桃‘No.120'幼胚胚轴与子叶体细胞胚胎发生及其植株再生

核桃 (Juglansregia)‘No . 12 0’品系授粉 7～ 8周的幼胚胚轴与子叶在含不同植物生长调节剂组合的诱导培养基上培养 4周后转移至无植物生长调节剂的继代培养基上培养 ,不同发育时期的体细胞胚直接形成于胚轴与子叶表面。子叶与胚轴分别在KT 2mg/L BA1mg/L IBA 0 .0 1mg/L与 2 ,4 D 2mg/L KT 1mg/L的组合的诱导下体细胞胚胎发生频率最高。体细胞胚经 3～ 5℃低温处理 2个月 ,31.6%的体细胞胚能发育成正常生长的植株     

基于广义混合效应模型的云冷杉林天然更新计数方法研究

天然更新是森林恢复较好的办法,对未来林分结构和生物多样性具有深远的影响。更新模型能够模拟天然更新的现实和未来状况,为森林经营者提供准确的森林计划。以吉林省汪清林业局2013年设置的12块云冷杉针阔混交林为例,选择泊松和负二项分布形式,考虑样地间的随机效应,构建基于林分因子的云冷杉针阔混交林天然更新模型。结果表明：各个树种对林分因子的反应不一,白桦更新株数与林分每公顷株数和平均直径均呈负相关;红松和水曲柳更新株数不受各个林分因子的影响,更新株数是随机的;冷杉更新株数与林分每公顷断面积呈负相关;色木槭和云杉更新株数均与林分平均直径呈负相关。在考虑样地的随机截距效应后,模型的模拟效果显著提高。在构建天然更新模型时,林分密度是十分重要的因子,如果要人工促进天然更新,就要科学合理的采取经营措施,以确保合理的林分密度。另外样地间的差异是不容忽略的因素,需要利用混合效应模型方法来降低预测误差。     

华富苹果离体叶片再生的主要影响因素研究

以花药培养选育的富士品种"华富"组培苗的叶片为试材,研究了离体叶片诱导再生不定芽过程中不同激素种类与组合、暗处理时间等因素对不定芽再生率的影响。结果表明:试管苗继代培养3～4代,取顶部嫩叶3～4片,剪除叶片边缘,叶片以近轴面接种到最佳诱导再生培养基MS+TDZ 2.0mg/L+IAA 0.75mg/L+蔗糖30g/L,pH值5.8,黑暗培养10～15d后,转入光照培养条件下,再生率达83.3%～86.7%。再生不定芽分化15～20d后转接到增殖培养基MS+BA 0.5mg/L+IBA 0.1mg/L上,当不定芽长度约2cm时再转接到生根培养基1/2MS+IAA 1.0mg/L+蔗糖2%,15d后,生根率可达95.0%以上。     

大青山林区米老排人工林伐桩萌芽更新研究

以33年生米老排伐桩为研究对象,分析了不同伐桩基径(≤30 cm、30＜X≤40 cm、40＜X≤50 cm、＞50 cm)及伐桩高度(≤5 cm、5＜Y≤10 cm、10＜Y≤20 cm、＞20 cm)对其萌芽植株数量、胸径及高度等生长状况的影响。结果表明,4个不同的伐桩基径级之间,30＜X≤40 cm其萌芽植株数量、胸径及高生长较大;伐桩基径对其萌芽植株数量影响差异显著,但对胸径及高生长影响差异不显著。伐桩高度在≤5 cm和5＜Y≤10 cm时,其萌芽植株数量、胸径及高生长较大,且随着伐桩高度的增加而降低。     

哈密大枣叶片不定芽再生体系研究

建立哈密大枣叶片离体再生体系,为遗传转化奠定基础.采用哈密大枣叶片为外植体,研究基本培养基、激素浓度、暗培养时间、AgNO3等因素对离体叶片不定芽诱导的影响,并获得再生植株.MS、NN69、WPM三种培养基相比较,NN69更适合做为诱导愈伤组织的基本培养基;TDZ诱导叶片再生不定芽的效果显著优于 BA;再生培养基中添加1 mg/L AgNO3对不定芽的形成有显著的影响（P ＜0．05）;培养初期经过2周避光培养更有利于提高再生效率;采用10 mg/L维生素 C浸泡15 min可以防止褐化,并能提高不定芽再生率;培养基中添加聚乙烯吡咯烷酮（PVP）或者维生素C,不定芽再生率无显著提高（P ＞0．05）;培养基添加活性炭（AC）会抑制外植体的分化.叶片在 NN69＋1．0 mg/L TDZ＋0．20 mg/L IBA＋AgNO31．0 mg/L培养基上,暗培养2周后转入光照培养,出芽外植体转入 MS＋1 mg/L 6GBA＋0．20 mg/L IBA 不定芽再生效果最好.不定芽生长至3 cm 以上时,转至0．40 mg/L IBA的1/2MS培养基上进行诱导生根.     

西葫芦双单倍体自交一代离体再生研究

以西葫芦DH12-11409双单倍体植株自交后代种子为试材,研究不同激素组合、外植体类型和苗龄对诱导西葫芦不定芽再生以及不定芽生根的影响。结果表明,取5d龄西葫芦双单倍体黄绿色子叶的子叶节为外植体,在MS+30g/L Suc+8g/L Agar+2.0mg/L 6-BA+0.1mg/L NAA培养基上诱导不定芽效果最好,诱导率高达90.0%,分化系数为8.5;生根培养基则以MS培养基中添加0.05或0.1mg/L NAA为宜;5~6片真叶再生植株经驯化移栽成活率高达90.0%,为再生植株驯化移栽的最佳时期。     

Dynamics and determinants of Quercus alba seedling success following savanna encroachment and restoration

The scattered tree layer that defines savannas is important for structuring the understory community and determining patterns of overstory recruitment. However, encroachment by woody plants has altered overstory tree densities and regeneration dynamics. We characterized seedling success of the savanna-forming species Quercus alba within Midwestern (USA) oak savannas that had been degraded by encroachment (control; n = 4) or experimentally restored by removal of encroaching woody vegetation (treatment; n = 4). In early 2004, 981 seedlings were transplanted along transects radiating from tree boles of overstory Q. alba trees to inter-canopy gaps and monitored for three growing seasons. Seedlings in restored sites had greater survival (>2×), height growth (by >50%), and basal diameter growth (by >20%). In general, seedling survival and growth parameters increased with distance from overstory trees and were greatest in inter-canopy gaps of restored sites. By the final growing season (2006), the seedling survival-by-distance from tree correlation was stronger in control (r² = 0.25) than treatment sites (r² = 0.18), due to relatively uniform (and greater) survival at all distances from trees in treatment sites. In 2006, growth parameters (seedling height, diameter, Δ height, Δ diameter, and # leaves) were significantly (and more strongly) positively correlated with distance from trees in treatment sites. However, seedling herbivory was also greater after treatment and increased with distance from overstory trees. To understand seedling/microenvironment relationships, we created logistic (survival) and linear regression models (Δ height, Δ basal diameter, # leaves in 2006). Control seedling models had consistently greater predictive power and included more variables, suggesting that savanna restoration may decouple seedlings from their microenvironments, potentially by decreasing competition for limiting resources. Encroachment of the savannas in this study is limiting regeneration of Q. alba, suggesting substantially altered regeneration dynamics from those under which these savannas originally formed. Initial responses from our test of restoration, however, were promising and mechanical encroachment removal may be a means to promote overstory regeneration of this species. Finally, the savannas in this study appear inherently unstable and a scattered canopy tree configuration is unlikely to persist without regular disturbance, even in the restoration sites. Repeated mechanical thinning treatments with selected retention of recruiting Q. alba individuals or reintroduction of understory fire or grazing animals may be potential mechanisms for promoting long-term persistence of savannas at these sites.     

昌红苹果离体叶片不定芽的诱导及植株再生

 以昌红苹果的组培苗为试材,研究建立叶片的离体再生体系。用30~40 d继代的新梢顶部1~3节新展开的叶片作为外植体,分别接种在分化的培养基上,黑暗处理15 d, 昌红苹果叶片不定芽的最高再生率为100%。在6号培养基上,昌红苹果叶片的再生能力最高; 诱导叶片不定芽适宜的培养基为MS+TDZ 1.0 mg /L+NAA 0.5 mg/L+蔗糖 30 g/L+ 琼脂 5.5 g/L。