航天诱变凤仙花叶片形态特性初探

以搭载"神舟四号"飞船后选育获得的凤仙花突变体后代为材料,对其叶型基本特性进行观察测量。结果表明,与对照相比,诱变凤仙花后代叶片长宽比、叶片厚度均发生显著变异;气孔宽度无显著差异,长度差异极显著。叶片形态特征的变化也在一定程度上导致凤仙花离体叶片萎蔫曲线的不同,对照凤仙花水分短时间内散失更快,诱变凤仙花失水速率则更为均匀缓慢。通过对叶片形态的研究,说明诱变后凤仙花的叶型变化是一种有利突变。     

Flight and Oviposition Behavior of the Adult Maritime Ringlet (Coenonympha nipisiquit McDunnough) Females in Response to Microhabitat

Maritime ringlet butterflies (Coenonympha nipisiquit McDunnough), an endangered species in Canada, inhabit salt marshes, which consist of microhabitat mosaics with varied larval survival rate. These microhabitats may influence the movement and reproductive behaviors of females, which in turn may affect population dynamics. I recorded behaviors and locations of females every minute with a GPS rover and calculated their move lengths and turning angles. Move lengths did not change in response to microhabitats, although turning angles became larger near bodies of water with sparse vegetation. Females spent a longer time in one location and oviposited more often where the principal larval host, Spartina patens (Aiton) Muhl., is abundant, regardless of larval survival rate. Older females tended to initiate flight more readily than younger females and spent more time flying and nectaring. Younger females were more fecund and spent a longer time at one location. Because young females tend to be less mobile and more fecund, the majority of oviposition should take place near eclosion sites. However, some eggs will be laid away from microhabitats favorable to larval survival when older females become mobile and move out of their natal microhabitats. Because it seems to have little potential to colonize new habitat on its own, monitoring population dynamics and habitat quality will be crucial for the persistence and recovery of this rare species.     

Defense Responses in Rice Induced by Silicon Amendment against Infestation by the Leaf Folder Cnaphalocrocis medinalis

Silicon (Si) amendment to plants can confer enhanced resistance to herbivores. In the present study, the physiological and cytological mechanisms underlying the enhanced resistance of plants with Si addition were investigated for one of the most destructive rice pests in Asian countries, the rice leaf folder, Cnaphalocrocis medinalis (Guenée). Activities of defense-related enzymes, superoxide dismutase, peroxidase, catalase, phenylalanine ammonia-lyase, and polyphenol oxidase, and concentrations of malondialdehyde and soluble protein in leaves were measured in rice plants with or without leaf folder infestation and with or without Si amendment at 0.32 g Si/kg soil. Silicon amendment significantly reduced leaf folder larval survival. Silicon addition alone did not change activities of defense-related enzymes and malondialdehyde concentration in rice leaves. With leaf folder infestation, activities of the defense-related enzymes increased and malondialdehyde concentration decreased in plants amended with Si. Soluble protein content increased with Si addition when the plants were not infested, but was reduced more in the infested plants with Si amendment than in those without Si addition. Regardless of leaf folder infestation, Si amendment significantly increased leaf Si content through increases in the number and width of silica cells. Our results show that Si addition enhances rice resistance to the leaf folder through priming the feeding stress defense system, reduction in soluble protein content and cell silicification of rice leaves.     

蜘蛛对稻纵卷叶螟和白背飞虱的选择捕食作用

讨论蜘蛛的主要种群拟水狼蛛、食虫瘤胸蛛、粽管巢蛛对稻纵卷叶螟、白背飞虱的选择捕食特性。由结果可见：猎物被捕食量与参试种群编码值（密度）的数量关系可由二次多项式模型技术。当取每科水稻上有稻纵卷叶螟５头,白背飞虱１０头,拟水狼蛛２头,粽管巢蛛２头,食虫瘤胸蛛２头时,蜘蛛种群对白背飞虱有较大的选择捕食比率。     

Leaf Export and Partitioning Changes Induced by Short-Term Inhibition of Phloem Transport

Both electric shock and cold shock applied to the phloem pathway,and known to induce temporary inhibition to long-distance phloemtransport, are shown to have an immediate and sustained effectupon both export of carbon from the leaf and its partitioningbetween alternative sinks. The changes in export occurred byan unknown mechanism, while the changes in partitioning areinterpreted as responses to changed export Key words: Carbon partitioning     

Effects of Leaf Age on Oviposition and on Offspring Fitness in the Imported Willow Leaf Beetle Plagiodera versicolora (Coleoptera: Chrysomelidae)

Imported willow leaf beetles Plagiodera versicolora oviposit on willow leaves, and both larvae and adults feed on the leaves. In the field, eggs were found on leaves near the center of branchlets, and the number of eggs per cluster was independent of the leaf area and position. However, in the laboratory, females chose young leaves over old leaves, for both oviposition and feeding and choice did not rely on information on relative position or size of leaves. Developing on young versus old leaves may provide both advantages and disadvantages. In the laboratory, larvae developed more quickly and attained a greater adult weight when fed young versus old leaves, perhaps because of increased mandibular wear of larvae fed old leaves. However, in the field, survival of eggs was lower on young versus old leaves. In the laboratory, rates of cannibalism and survivorship to adulthood did not differ on young versus old leaves.     

Cry1Ab蛋白对稻纵卷叶螟幼虫体内三种保护酶活性的影响

室内采用酶活力测定方法研究转B t基因水稻表达的Cry1Ab蛋白对稻纵卷叶螟幼虫体内3种保护酶(AChE、SOD和CAT)活性的影响。结果表明,用转B t基因水稻处理稻纵卷叶螟幼虫,饲喂4 h、36 h后,其体内AChE活力分别比对照增加了52.09%、128.51%,并且都极显著(P<0.01)高于对照组;取食转基因水稻叶片4 h后,幼虫体内SOD酶活性比对照提高了91.5%,与对照有显著差异;36 h后活性达到最大值,但与对照差异不显著。取食转基因水稻叶片24 h后,幼虫体内CAT酶活性达到最大值且高于对照,但与对照差异不显著;48 h后酶活性受到显著抑制,与对照差异显著。同时,测定了幼虫体内及其粪便中Cry1Ab蛋白含量的变化,结果表明,取食转基因水稻叶片12 h后,进入体内的Cry1Ab蛋白随粪便排出,幼虫体内的Cry1Ab蛋白含量一直低于粪便中的含量,且在24 h时两者差异达到最大。由于Cry1Ab蛋白在幼虫体内的积累,扰乱了稻纵卷叶螟幼虫体内AChE、SOD和C AT保护酶的动态平衡,使虫体内自由基的清除遇到障碍,从而对其产生毒害作用。     

航天诱变凤仙花总RNA的提取及RT-PCR初探

目的：为研究凤仙花的突变性状,克隆相关突变基因,探讨了凤仙花总RNA的提取方法,并利用RT—PCR克隆花色调控基因。方法：对加拿大BBI和日本TaKaRa公司提供的RNA提取试剂盒进行实验比较并适当改良,提取高质量的凤仙花总RNA。结果：提取到较高质量的凤仙花总RNA,克隆了其花色调控基因。结论：用改进的方法提取的总RNA质量较好,能用于基因克隆等相关实验。     

Biochemical and Morphological Features of Rice Cell Death Induced by Pseudomonas avenae

Pseudomonas avenae is a Gram-negative phytopathogenie bacteriumthat causes the symptom of a brown stripe in infected susceptibleplants. The host range of P. avenae is wide among the monocotyledonousplants, however, individual strains can infect only one or afew host species. A rice-incompatible strain, N1141, causedrapid cell death in sheath sections and in cultured rice cells.A rice-compatible strain, H8301, also induced cell death, however,this cell death in a compatible interaction was delayed comparedto the cell death induced by the N1141 incompatible strain.Inoculation of N1141 strain induced expression of EL2 gene whichis thought to be one of the defense-related gene. Terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL) of culturedrice cells showed that DNA cleavage occurred only in N1141-inoculatedrice cells. N1141 strain caused cytoplasmic condensation, shrinkage,and plasma membrane blebbing, all of which are important morphologicalcharacteristics of programmed cell death (PCD). In contrast,H8301 strain inoculated rice cells appeared to show weakeningof the cell wall instead of cytoplasm condensation, shrinkageand membrane blebbing. These results suggest that the rapidcell death of rice induced by the incompatible strain is characterizedas PCD. (Received May 22, 1999; Accepted July 22, 1999)     

激活蛋白处理水稻引发基因差异表达的研究

利用抑制性消减杂交技术(Suppression Subtractive Hybridization,SSH)成功构建了植物激活蛋白处理水稻与非处理组水稻中差异表达的消减cDNA文库。从文库中一共筛选到1756个克隆,通过反向Northern杂交,从中得到264个有效克隆并测序,利用BLAST在GenBank数据库进行序列相似性比对分析,获得28个上升表达差异基因。通过分析这些基因与植物的光合作用、营养物质的运输代谢等多种植物的生理生化功能相关。本研究为揭示激活蛋白的作用机理奠定基础。     

Shear Modulus Estimation on Vastus Intermedius of Elderly and Young Females over the Entire Range of Isometric Contraction

Elderly people often suffer from sarcopenia in their lower extremities, which gives rise to the increased susceptibility of fall. Comparing the mechanical properties of the knee extensor/flexors on elderly and young subjects is helpful in understanding the underlying mechanisms of the muscle aging process. However, although the stiffness of skeletal muscle has been proved to be positively correlated to its non-fatiguing contraction intensity by some existing methods, this conclusion has not been verified above 50% maximum voluntary contraction (MVC) due to the limitation of their measurement range. In this study, a vibro-ultrasound system was set up to achieve a considerably larger measurement range on muscle stiffness estimation. Its feasibility was verified on self-made silicone phantoms by comparing with the mechanical indentation method. The system was then used to assess the stiffness of vastus intermedius (VI), one of the knee extensors, on 10 healthy elderly female subjects (56.7±4.9 yr) and 10 healthy young female subjects (27.6±5.0 yr). The VI stiffness in its action direction was confirmed to be positively correlated to the % MVC level (R² = 0.999) over the entire range of isometric contraction, i.e. from 0% MVC (relaxed state) to 100% MVC. Furthermore, it was shown that there was no significant difference between the mean VI shear modulus of the elderly and young subjects in a relaxed state (p>0.1). However, when performing step isometric contraction, the VI stiffness of young female subjects was found to be larger than that of elderly participants (p<0.001), especially at the relatively higher contraction levels. The results expanded our knowledge on the mechanical property of the elderly’s skeletal muscle and its relationship with intensity of active contraction. Furthermore, the vibro-ultrasound system has a potential to become a powerful tool for investigating the elderly’s muscle diseases.     

Relation between Leaf Age and Nitrogen Incorporation in the Leaf of the Rice Plant (Oryza sativa L.)

The relation between leaf age and the incorporation of nitrogeninto the leaf was examined in the 13th leaf blade of the riceplant, Oryza sativa L., after feeding it ¹⁵N-labelled ammoniumsulfate. The incorporation of nitrogen into the leaf was activeup to the maximum leaf nitrogen content; thereafter it decreasedquickly. At the beginning of senescence, when the nitrogen contentof the leaf had begun to decrease, the incorporation of ¹⁵Ndecreased to 28% of the value during development. At the middlestage of senescence, when the nitrogen content had decreasedto half the maximum, the incorporation was 13%. The incorporation of ¹⁵N into soluble proteins was examinedby gel filtration on Sephadex G-200. During development, largeamounts of ¹⁵N were incorporated into the ribulose bisphosphatecarboxylase-rich fraction. As the leaf aged, the incroporationof ¹⁵N into this fraction decreased more sharply than it didin other fractions. This tendency was more pronounced at thelate stage of senescence. We concluded that the amounts andkinds of protein synthesized in a leaf are closely related toleaf age. (Received November 24, 1981; Accepted June 17, 1982)     

秋水仙素诱导不结球白菜叶片形态类型与染色体加倍的关系

以二倍体不结球白菜‘依伶’为材料,用0.2%秋水仙素溶液处理子叶期生长点,研究不结球白菜在形态学上对秋水仙素诱导的响应及动态变化。结果表明:(1)‘依伶’对秋水仙素诱导的响应均以幼苗期前4片真叶中出现变异特征叶的形式表现,诱导处理15d后出现了圆盘状、豆瓣状、棒状3种响应类型;处理30d后,以上3种类型分别分化出长勺状、花状、圆锥状类型。(2)分化前后3种响应类型受秋水仙素抑制程度不同导致生长速率各不相同,生长速率的顺序分别为:圆盘状>豆瓣状>棒状,花状>长勺状>圆锥状,6种响应类型的特征叶逐渐萎蔫死亡,继续生长的其他.叶生长正常。(3)豆瓣状、圆盘状、长勺状、棒状、花状、圆锥状6种叶片形态响应类型于处理当代选株中四倍体加倍率依次分别为50.00%、41.67%、25.00%、16.67%、8.33%、0.00%。研究表明,早期筛选宜选用圆盘状、豆瓣状变异植株。     

水稻幼穗组培及白化苗的电镜观察

木文报道了五份水稻材料的幼穗组培的诱导率和分化率,对继代８次后的幼穗愈伤分化出的白苗和绿苗及其各自的愈伤进行电镜扫描,发现白苗的质体结构不完整,不能正常合成叶绿素。