咖啡黑小蠹的发生规律及药剂防治研究

咖啡黑小蠢是近年在兴隆华侨农场严重危害中粒种咖啡的重要害虫。据1989年对4—5年生咖啡树调查,植株受害率100％,枝条受害率29.7—82.5％,虫害枯枝率7.65—17.8％。该虫以雌成虫钻蛀咖啡枝条为害,幼虫和成虫取食蛀道壁上的真菌菌丝。田间种群数量通常在3月上旬开始剧增,3月中下旬为高峰期,7月至10月田间虫口极少,11月以后逐渐有虫口及虫枯枝出现。温度是影响虫口波动的主要因素。2.5％溴氰菊酶、25％杀虫双、40％乐菊酯各兑水1000倍对成虫直接触杀效果显著,死亡率均为100％。48％乐斯本、40％氧化乐果400—800倍液等12种杀虫剂田间喷雾对咖啡枝条蛀洞内的成虫、蛹、幼虫防效均不明显。     

香笋竹人工培育技术及产业化开发方案研究

香笋竹是云南特产优质笋用竹种,也是箭竹属中秆型较大和分布海拔较低的一种。由于具有鲜笋品质优良、抗寒性强、秋季发笋等特点,开发价值较高。文中报道了香笋竹基本生物学特性和人工培育技术试验的阶段性成果,提出和论述了产业化开发方案。     

华西箭竹对岷江冷杉林主要乔木树种幼苗结构及分布格局的影响

在亚高山岷江冷杉林中选取≤50 m2、50～150 m2和＞150 m2的林窗,每种类型内都包含3种华西箭竹盖度(≤20%、20%～50%和＞50%),共调查林窗9个.通过野外群落学调查,研究林窗内岷江冷杉、糙皮桦和川滇长尾槭这3种主要乔木树种幼苗的结构和分布格局.结果表明:1)在华西箭竹盖度大的林窗中,3个树种的各高度级幼苗都不多,林窗形成后,绝大多数林窗被华西箭竹植株定居,竹盖度对主要树种幼苗总密度以及岷江冷杉幼苗密度的影响显著(p＜0.05);2)华西箭竹盖度对岷江冷杉幼苗密度的影响最明显,主要是由于3个树种的生态学特性存在差异,岷江冷杉在没有华西箭竹分布或箭竹盖度小的地方优先更新;3)3种幼苗在9个林窗几乎全为聚集分布,这主要取决于幼苗生物学特性及林窗环境.林窗大小和华西箭竹盖度的综合作用对优势树种幼苗的结构和分布格局产生影响.     

王朗林区人工缺苞箭竹亚层数量特征及其模型

王朗林区人工缺苞箭竹亚层数量特征及其模型刘兴良，向性明（四川省林业科学研究院成都６１００８１）关键词四川王朗，亚高山暗针叶林，亚建群层，缺苞箭竹，大熊猫，仿真造林缺苞箭竹（Ｆａｒｇｅｓｉａｄｅｎｕｄａｔａ）是四川王朗林区亚高山暗针叶林下亚建群层的主要...     

麻楝蛀斑螟成虫的羽化节律及生殖行为

在温度（25±1）℃,光暗周期L：D=14：10（光期06：00开始,20：00结束）,相对湿度RH=75％-80％的条件下,观察了麻楝蛀斑螟成虫的羽化与生殖行为．结果表明：成虫羽化率85．4％,羽化期25d左右;羽化行为主要出现在暗期,日羽化高峰在20：00-23：00,占总羽化量的80．7％;雌、雄比例0．83：1．羽化后第2天达到性成熟,当天羽化的成虫未发生交配;交配发生在进入暗期5-8h,交配持续时间50—200min;随着日龄的增大,交配率降低,交配持续时间增长;交配后第2天开始产卵;雌、雄虫均未发现2次交配现象．交配雌虫平均产卵104粒,卵期7d左右,孵化率84．3％;未交配雌虫平均产卵157粒,孵化率0．交配雌虫和雄虫的平均寿命为3．73和2．93d,未交配雌虫和雄虫的平均寿命为5．87和5．03d．     

不同浓度IBA和扦插深度对桉树嫩枝扦插的影响

采用随机区组试验,研究了不同浓度IBA和扦插深度对桉树嫩枝扦插成活的影响。结果表明,不同浓度IBA对桉树扦插成活有显著影响,以4 000mg·L-1IBA速蘸嫩枝扦插效果最好,生根率达到了92.23%;不同扦插深度对桉树生根率有显著影响,以扦插深度为4cm时效果最佳,生根率达到了86.19%。     

缺苞箭竹生长发育规律初步研究

缺苞箭竹是大熊猫最喜食的竹种之一,主要分布于四川的岷山山系,构成冷杉林下的主要层片。通过两年的定位观测发现: 1.在春季,缺苞箭竹地下部分生长是最活跃的,它包括秆基笋芽的萌发和上年萌发笋芽的走“鞭”发笋。 2.地上部分秆茎生长分为四个阶段,即延缓期,指数生长期,相对生长下降期和休眠期。在第二阶段生长最快,生长量最大,占年高生长量的92％,日最大高生长量为6.1cm。这一阶段的最大特点是气温和生长波动的高度协调。在不同立地条件下这一生长期长短是不同的。 3.通过箭竹生长与气温,太阳辐射,降水等气候因子的回归分析,结果表明:温度是支配箭竹生长的主导因素。     

华西箭竹(Fargesia nitida)种子特征及其萌发特性

华西箭竹(Fargesia nitida)是大熊猫天然采食的主要竹种之一,由于开花习性独特,对其种子的研究报道还很少见。对华西箭竹种子的基本特征及不同温度下的萌发特性进行了研究。结果表明:华西箭竹种子长为(5.01±0.43)mm、宽(1.99±0.18)mm、厚(1.72±0.13)mm、千粒重(11.51±0.07)g;风干种子的化学组成:水分含量为(10.22±0.36)%、淀粉(74.52±0.57)%、粗蛋白(7.54±0.32)%、粗脂肪(3.71±0.17)%、可溶性糖(2.94±0.21)%、其他成分仅占(1.04±0.01)%。其种子萌发的适宜温度为20~25℃;低于20℃或高于25℃,种子的萌发率都会下降。     

Identification of PCR-based markers linked to the powdery-mildew-resistance gene Pl1 from Malus robusta in cultivated apple

The availability of molecular markers linked to mildew resistance genes would enhance the efficiency of apple-breeding programmes. This investigation focuses on the identification of random amplified polymorphic DNA (RAPD) markers linked to the Pl₁ gene for mildew resistance, which has introgressed from Malus robusta into cultivated apples. The RAPD marker technique was combined with a modified ‘bulked seg-regant analysis’ mapping strategy. About 850 random decamer primers used as single primers or in combinations were tested by PCR analysis on the basis of resistant and susceptible DNA pools. Selected primers producing RAPD fragments were applied in an additional selection step to M. robusta and genotypes representing intermediate breeding stages of the breeding population 93/9, for which a 1:1 segregation could be observed for the resistance trait. Seven RAPD markers, all representing introgressed DNA sequences from M. robusta, were identified and arranged with the Pl₁ locus in a common linkage group. The two most tightly-linked RAPD markers, OPAT20₄₅₀ and OPD2₁₀₀₀ were mapped with a genetic distance of 4.5 and 5 cM, respectively, from the Pl₁ gene. Both markers are suitable for marker-assisted selection in apple breeding. The polymorphic DNA fragment OPAT20₄₅₀ was cloned and sequenced, and longer primers for the generation of a sequence-characterized amplified region (SCAR) marker have been constructed; this marker was easier to score than the original RAPD marker.     

Identification of marker alleles linked to fire blight resistance QTLs in apple genotypes

Molecular marker analysis can be an effective tool when searching for new fire blight resistance donors. It can speed up the breeding process as well, even though many of the available markers linked to fire blight resistance QTLs have not yet been tested by screening a large number of cultivars. The aim of this study was to search for alternate sources of the three major QTLs of fire blight resistance; FBF7, FB_MR5 and FB_E, as well as to test the efficiency of some markers linked to minor QTLs. Altogether, nine primer pairs were used on 77 genotypes including new Hungarian cultivars and old apple cultivars from the Carpathian basin. Several marker alleles of FB resistance QTLs have been detected in the screened genotypes, most importantly the alleles coupling with FB_MR5 in the old cultivars ‘Kéresi muskotály’, ‘Szabadkai szercsika’ and ‘Batul’. We propose these cultivars as the first available resistance donors of FB_MR5 instead of the crabapple Malus × robusta 5. The results also bring new information regarding the resistance alleles of new Hungarian cultivars and selections.