金乌贼成体副缠卵腺的超显微结构

采用组织学和电镜技术对金乌贼(Sepia esculenta)成体副缠卵腺的结构进行了研究。结果显示,(1)解剖结构显示,副缠卵腺呈耳状,下端呈‘M’型与缠卵腺紧密连接,颜色为白色并夹杂着橙黄色;(2)显微结构显示,副缠卵腺由腺壁、腺体小管和结缔组织构成,腺壁由外向内依次为外膜层和肌肉层,其中,外膜层由单层柱状上皮细胞组成;腺体小管数量较多,平均直径为70μm,内腔表面可见微绒毛层,管腔内含有大量的分泌物质;结缔组织具有集中分布的血管和肌肉纤维;(3)超微结构显示,上皮细胞细胞质中含有数量较多且分布集中的囊泡,部分囊泡中含有分泌球状体;微绒毛分布面积较广且排列密集,而纤毛一部分集中分布,另一部分呈单行排列,着生不连续;腺体小管管腔内具有大量的共生菌,绝大部分为球菌,且在管腔中具有较多的分泌球状体。研究表明,金乌贼副缠卵腺是一种起分泌作用的腺体,存在的共生菌据认为在胚胎发育阶段的病害防治方面具有一定作用。     

试管芋诱导的研究

 以芋组培苗为试材, 研究了蔗糖浓度、激素浓度、光照时间、培养温度、不同大小试管苗,不同芋品种类型等因素对试管芋诱导的影响及不同基质对试管芋育苗成活率的影响。结果表明: 诱导试管芋较理想的培养基为MS + 蔗糖8 % + BA 1. 0 mg·L ^{- 1} + NAA 0. 5 mg·L^-1 , 光照12 h/ d , 培养温度30 ℃; 试管苗越大越有利于试管芋的形成; 试管芋可保持其原有的特性; 基质影响试管芋育苗的成活率, 4 种基质中蛭石最好。     

侵染木薯的两种单组分菜豆金色花叶病毒属病毒及卫星分子基因组结构特征分析

为明确木薯(Manihot esculenta Crantz)植株叶片皱缩、畸形是否由菜豆金色花叶病毒属病毒侵染引起,从云南省红河州田间采集具有疑似感染症状的木薯植株叶片样品,应用菜豆金色花叶病毒属病毒简并引物、种专化性引物及卫星分子引物进行PCR扩增、克隆,通过测序分析其核苷酸序列特征并对其进行系统进化分析.结果 显...     

菰黑粉菌MAPKK同源基因UeMkk1的全长克隆及表达

菰黑粉菌(Ustilago esculenta)是菰(Zizania latifolia)植株体内的内生真菌,其二型态转换与茭白孕茭密切相关,而丝裂原活化蛋白激酶(mitogen activated protein kinase,MAPK)途径在真菌二型态转换中具有重要调控作用.本研究利用酵母型及菌丝型菰黑粉菌的差异蛋白表达及转录组分析数据,克隆了菰黑粉菌中一个丝裂原活化蛋白激酶激酶(mitogen activated protein kinase kinase,MAPKK)基因UeMkk1(GenBank登录号:KR870332).该基因cDNA序列全长2 204 bp,开放阅读框2 043 bp.与模式菌酵母的MAPK途径蛋白进行聚类分析表明,UeMkk1属于MAPKK蛋白,NCBI中Blast比对结果及进一步的系统发育分析表明,UeMkk1与黑粉菌属真菌的Mkk1同源性较高,其中与大麦坚黑穗病菌(Ustilago hordei)的MKK1一致性达到84％,其丝/苏氨酸双特异性蛋白激酶催化结构域在不同真菌中高度保守.同时,本研究通过大肠杆菌(Escherichia coli)原核表达系统成功表达并从蛋白裂解上清液中纯化得到了纯度较高的UeMkk1蛋白.另外,对不同碳源诱导后菰黑粉菌的生长特征观察及UeMkk1的表达分析表明,蔗糖能诱导菰黑粉菌菌丝的形成及生长,UeMkk1的表达量在菌丝生长后期下调表达;PDA、葡萄糖及麦芽糖培养基中菰黑粉菌保持酵母型生长,UeMkk1呈周期性上调表达.以上研究工作为进一步开展UeMkk1基因的功能研究,阐明其在菰黑粉菌二型态转换及茭白孕茭中的作用提供了基础材料.     

利用茭白薹管结构差异快速辨别雄茭的方法

为了提高茭白产量,需要寻找一种快速辨别雄茭的方法。本试验在比较茭白的雄茭与正常茭、灰茭薹管内部结构差异的基础上,通过田间试验验证了薹管内部结构差异与茭白孕茭的关系:正常茭、灰茭的薹管髓腔内有丝状物,而雄茭薹管髓腔内则完全没有丝状物。髓腔内有丝状物的薹管均能孕茭,无丝状物的薹管则不能孕茭。利用薹管髓腔内有无丝状物可以快速区分出雄茭薹管,是一种高效快速辨别雄茭的新方法。     

木薯的胚胎学研究 Ⅰ．小孢子的发生和雄配子体的发育

木薯（ＭａｎｉｈｏｔｅｓｃｕｌｅｎｔａＣｒａｎｔｚ）雌雄同株、雄蕊十枚、花药四室。抱原细胞单列．初生造孢细胞不经分裂、直接发育成一纵列的小抱子母细胞。小孢子母细胞减数分裂为同时型，四分体为四面体形。腺质绒毡层。成熟花粉粒二细胞型。萌发孔多个，分散于外壁突起的三角形瘤状物之间，数个瘤状物构成巴豆图案，部分花药发育出现异常。     

菰黑粉菌不同菌株比较研究

从野生茭、单季茭、双季茭及灰茭中分离7个菌株,比较了其冬孢子的萌发率、菌落的形态、在不同温度下该菌的生长情况。研究表明,从野生茭和灰茭上分离的菌株与正常茭的菌株存在较大差异。初步认为灰茭和正常茭是由黑粉菌不同生理小种引起。     

The Components and Deployment of Resistance to Cassava Mosaic Virus Disease

Cassava mosaic virus disease (CMD) is prevalent and causes serious losses in cassava (Manihot esculenta) in southern India and in many parts of sub-Saharan Africa. The disease is caused by viruses of the Geminiviridae that are transmitted by the whitefly Bemisia tabaci and disseminated in the stem cuttings used routinely for propagation. The main approach to control is through the use of virus-resistant varieties, but suitable ones are not always available and susceptible varieties are still widely grown. This explains why CMD continues to be a problem in many areas.CMD-resistant varieties have several features which are considered in this review:- They are not readily infected, even when exposed to large amounts of vector-borne inoculum. When infected they develop symptoms that tend to be inconspicuous and not associated with obvious deleterious effects on growth or yield. Moreover, the symptoms become even less conspicuous as growth proceeds and plants may eventually recover and become symptomless. Infected plants support a low virus content and they are likely to be a poor source of inoculum from which further spread can occur. Virus is not fully systemic within infected plants which can be a source of uninfected planting material when stem cuttings are collected for further propagation. This phenomenon is referred to as reversion and it has an important cleansing effect in restricting or preventing the progressive deterioration in health status that would otherwise occur during successive cycles of vegetative propagation.The available information on the different components of resistance is discussed and it is concluded that they are inter-related features of the same basic mechanism that restricts virus entry, replication and movement within the host. It is argued that the effectiveness and durability of virus-resistant varieties are likely to be influenced by the way in which they are deployed. However, this topic has received little attention from researchers and there is continuing uncertainty on the effects of CMD on the yield of resistant varieties and on the role of phytosanitation. This involves the use of virus-free planting material and the removal (roguing) of any additional diseased plants that occur. Some consider that these procedures complement the use of virus-resistant varieties and should be adopted, whereas others argue that they are unnecessary and inappropriate. It is concluded that there is considerable scope for utilizing resistant varieties more widely and more effectively than at present, but in doing so it is important to avoid eroding the genetic diversity that is currently such a marked feature of cassava cultivation in Africa.     

崇明香酥芋茎尖培养和快速繁殖的研究

以崇明香酥芋为材料,研究消毒方式、茎尖直径、外植体接种时期、琼脂浓度、无机盐含量和活性炭浓度对芋茎尖分化和增殖的影响。结果表明：用饱和漂白粉溶液处理25min显著降低茎尖褐变率,而提高茎尖的分化率;芋茎尖直径0．3—0,5mm的分化率为51．7％;芋茎尖诱导的最佳时间为3～4月,茎尖分化率达64．4％;5．0g·L^-1的琼脂浓度茎尖的分化和试管苗的增殖显著高于其他处理;不同无机盐浓度显著影响茎尖褐变率,以1／2MS的茎尖分化率为最高;5．0g ·L^-1。的活性炭显著降低茎尖的褐变率,缩短转绿的时间并提高茎尖的分化率。