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1.
西葫芦的单花粉蛋白电泳   总被引:2,自引:0,他引:2  
对西葫芦(CucurbitapepoL.)的单花粉进行了蛋白电泳分析,结果表明在西葫芦花粉发育的不同阶段,其蛋白电泳图谱存在明显差异,结合细胞学观察结果,对这些差异进行了讨论。同时对同一杂合个体同一雄花相同发育阶段的不同花粉粒的蛋白电泳结果表明,它们之间也存在着差异。  相似文献   

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Maternal-environmental effects on subsequent progeny life-history traits were evaluated in squash ( Cucurbita pepo L.) in terms of the amount of time available for seed development, and the timing of fruit production. Progeny arising from three kinds of fruit were compared. Plants from which fruits were removed 3 d post-pollination throughout the growing season developed only 'late' fruits (during 10–15 d) at the end of the growing season; on control plants both 'early' and 'late' fruits developed (both types allowed to ripen fully). Seed from each type of fruit was weighed individually and categorized into three size classes, then germinated and raised to maturity, including regular harvesting of all fruits 3 d post-pollination. Maternal effects were evident for both vegetative and reproductive traits and carried over to later stages. In contrast, effects due simply to seed size disappeared by day 30 for leaf variables and day 60 for male flower production. Within a seed-size class, progeny arising from fruit of treated plants produced significantly more leaves, with greater size, and more male flowers than those arising from fruit of control plants, while the reverse was true for fruit number and fruit mass. This result is discussed in terms of possible gibberellic acid involvement. In control plants, progeny arising from seeds in the large, fully mature 'early' fruits produced significantly more, and larger leaves by day 30 than did those from late fruits (suggesting differential provisioning in seeds during development). Male flower production had a highly significant positive correlation with vegetative mass and a significant negative correlation with fruit production.  相似文献   

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N-ethylmaleimide (NEM) Lit 10-100 μ M led to a strong inhibition of the auxin-induced elongation growth of colcoptile segments, while fusicoccin-enhanced growth was not affected. Growth inhibition occurred only if NEM and auxin were allowed to act simultaneously. Preincubation of plant segments with NEM in the absence of auxin caused no inhibition of a subsequent growth stimulation by auxin, whenever NEM was removed before the application of IAA. However, preincubation with NEM plus auxin led to a remaining growth inhibition, which could not be reversed by a second auxin incubation in the absence of NEM. Fusicoccin added to NEM- plus auxin-treated segments was able to restore growth. It is suggested that auxin causes the unmasking of essential SH-groups of a protein to which NEM links covalently. thus inhibiting the growth process. This assumption was further supported by labeling experiments wish [14C]-NEM using membranes of maize ( Zea mays L. cv. Inraplus) coleoptiles. Two membrane fractions (S2= 480-1900 g; S4= 4300-15000 g) revealed a significantly higher [14C]-NEM labeling in the presence of auxin (2,4-diehlorophe-noxyacctic acid compared to 2,6 dichlorophenoxyacetic acid). This effect disappeared when the membranes were previously washed with EGTA [ethyleneglycolbis-(β-aminoethylether)-N,N,Nr',N'-tetraacetic acid]. The auxin-induced sensitization of coleoptilc segments against thiol-reagents and the auxin-induced expression of SH-groups of proteins of isolated membranes from coleoptiles arc suggested to be events involved in the primary action of auxins.  相似文献   

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通过光学显著 和扫描电镜,对新疆产双属9种植物的花粉形态进行了研究,发现该属花粉大多近球形,萌发孔多数,孔膜上有疣状突起,外壁纹饰为颗粒状,夹杂有小穴散布。  相似文献   

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鸡冠花叶蛋白质营养价值的评价研究   总被引:23,自引:2,他引:23  
应用模糊识别法和氨基酸比值系数法,分别以鸡蛋蛋白南为标准蛋白,以WHO/FAO氨基酸参考模式为评价标准,对3种鸡冠花叶蛋白质营养价值进行了全面评价,并与10种常见叶菜蛋白进行对照比较。结果表明,3种鸡冠花叶(干品)蛋白质含量为23.7% ̄27.4%,蛋白质中氨基酸种类齐全,其含量为83.47% ̄86.94%,必需氨基酸(EAA)占总氨基酸量的40.2% ̄41.7%,第一限制性氨基酸为含硫氨基酸(M  相似文献   

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锐劲特对青海省草原蝗虫防治价值的研究(英文)   总被引:1,自引:0,他引:1  
在过马营乡(青海省海南藏族自治州)对锐劲特控制草原蝗虫的作用进行了笼罩和野外实验。目的在于分析该新杀虫剂对草原蝗虫的作用方式,特效性及野外应用之最低剂量。红翅皱膝蝗(Angaracrisrhodopa),宽须蚁蝗(Myrmeleotettix palpalis)和狭翅雏蝗Chorthippus dubius被选用作实验材料。结果表明极低剂量的锐劲特(4 g和 8 g/ha活性物质)便对蝗虫有很强的触杀和胃毒作用。在笼内,两种不同浓度的锐劲特的药效几乎没有差别。除了宽须蚁蝗成虫,触杀的击倒作用一般较胃毒的迅速;锐劲特对狭翅雏蝗 5龄蝻的控制作用达 2周以上。在野外对 4个剂量的锐劲特(2,3,5和 10 g活性物质/ha)及 5个剂量的 20%的杀灭灵(90, 75, 60, 45, 30 g活性物质/ha)的短期防效进行了比较。锐劲特的短期防效较杀灭灵为好。不同剂量的锐劲特间的区别主要表现在处理后不同时间内蝗虫的死亡率,在短期控制效果上几乎没有差别。施用锐劲特26天后,喷洒过 3 g活性物质/ha以上剂量的实验小区内草原蝗虫的密度仍处于极低水平,表明该药野外施用的最低剂量为3g活性物质/ha。  相似文献   

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报道的叶肢介新属(Kenyaestheriagen.nov.)采自肯尼亚MajiyaChumvi地区的一钻孔,属下三叠统上马几牙楚姆维组(UpperMajiyaChumviFormation),其特征为壳瓣后背缘最后几条生长线靠近背缘处形成一个凹缘构造,但生长线在背缘并不反转弯曲,同时具有放射线纹饰,据此将其归于凹缘叶肢介科(Ulugkemiidae)。该科是一个灭绝的类群,分布于中泥盆统至上三叠统,古生代的类型都发现于欧亚大陆,晚三叠世的Triasulugkemia见于阿根廷,新属首见于早三叠世,也是在南大陆出现的第二例凹缘叶肢介类。孢粉Lunatisporitespellucidus和叶肢介AquilonoglyptaCorniaPalaeolimnadiaFalsisca组合指示含化石的地层时代为早三叠世早期。  相似文献   

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赤眼蜂防治小菜蛾适宜蜂种或品系的筛选(英文)   总被引:2,自引:0,他引:2  
以控制小菜蛾为目的,在实验室对29种赤眼蜂或品系进行了筛选。筛选评价根据5项指标:(1)能在小菜蛾卵上产卵的雌蜂比例,(2)每雌蜂寄生卵量,(3)子峰在每粒寄主上的存活率,(4)羽化率,和(5)子代性比。研究结果表明:有23种赤眼蜂或品系能够寄生小菜蛾卵,但无论在种间还是品系间均存在很大差异。根据5项筛选指标综合评价,29种中较好的为:前苏联的Trichogramma trjapitzni,美国的T.pretiosum,法国的T.nagarkattii,中国台湾的Trichogarammatoidea bactrae,中国广东的T.chilonis和法国的一个种T.sp。其中美国的T.pretiosum,中国台湾的Trichogarammatoidea bactrae,中国广东的T.chilonis可以考虑作为大田防治小菜蛾的首选蜂种。田间筛选及大田验证试验正在进行之中。  相似文献   

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根系温度对苋菜生长及光合特性的影响   总被引:5,自引:0,他引:5  
冯玉龙  姜淑梅  邵侠 《植物研究》2000,20(2):180-185
气候室中研究了根温对苋菜幼苗生长及光合等生理特性的影响。结果表明,苋菜幼苗生长曲线呈S形, 30d苗龄时生长最快, 40d苗龄时每株干、鲜重分别为0.45g和6.79g。20~25℃根温时40d苗龄苋菜生长最快,高根温对生长的危害大于低根温, 40℃根温苋菜根系生长、代谢受害严重。苋菜净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Cs)和胞间CO2分压(Pi)随根温的变化趋势基本一致, 20~25℃根温时,Cs、Pi、Pn和Tr均高,不良根温影响了Cs,使Tr降低, Pi降低,进而影响到Pn。回归分析表明, Pn与Cs、Pn与Pi、Tr与Cs、Pi与Cs均呈显著正相关。说明Cs下降是不良根温影响Pn的主要原因。  相似文献   

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江苏下扬子区笔石反射率研究   总被引:2,自引:1,他引:1  
通过对江苏下扬子地区笔石反射率的研究,发现随埋深增加笔石反射率增高,并建立了笔石反射率与牙形刺色变指标的对应关系,又以牙形刺色变指标与镜质体反射率之间的对应关系为“桥梁”,进一步建立了笔以射率与镜质体反率的对应关系,从而为下古生界烃源岩有机质成熟度的评价提供一项新的可靠的评价指标。  相似文献   

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Cadmium (Cd) is a toxic trace metal pollutant for humans, animals, and plants. Tobacco is a wellknown efficient accumulator of Cd and the genotypic differences in Cd uptake and the response to Cd was not determined. The objectives of this study were to investigate: 1) the effects of Cd on the growth and development of different tobacco cultivars; 2) the differences among tobacco cultivars in Cd concentration, uptake, and use for the phytoremediation of polluted soils with Cd; and (3) the interactions between Cd and Zn with respect to concentration and uptake. The Cd level affected the number of leaves and dry matter accumulation, and there were differences among the different cultivars that were used. Furthermore, some cultivars showed a higher reduction in growth than others, indicating that they are more sensitive to Cd level in the soil. Moreover, differences existed among the cultivars for the Cd concentration and uptake. There also were negative correlations between Cd and Zn concentrations; as Cd accumulation increased, Zn accumulation decreased, which showed that the two heavy metals were antagonistic. These results suggest that tobacco cultivars differed greatly in their growth and developmental responses to Cd and in the concentration and uptake of Cd and Zn. In addition, it is possible to use certain tobacco cultivars to lower the Cd concentration in the soil.  相似文献   

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濒危植物银杉的群落特征及其演替趋势   总被引:5,自引:2,他引:5       下载免费PDF全文
银杉(Cathayaargyrophyla)群落的外貌主要由具革质细型叶的常绿针叶中高位芽植物和具革质小、中型叶的常绿阔叶小、中高位芽植物所决定。其结构一般分为乔木层、灌木层和草本层,在有些群落内草本层不发育。组成银杉群落的高等植物有239种,半数以上的种类集中在杜鹃花科(Ericaceae)等9个科中。群落中热带型属的比重低于温带型属的比重,说明银杉群落虽然分布于亚热带,却具有较强的温带分布类型的性质。现有银杉群落处在演替系列的针叶混交林和针阔混交林两个阶段,过度干扰可能使针叶混交林逆向演替到灌丛阶段;处在针阔混交林阶段的银杉群落是相对稳定的亚顶极,将维持相当长的时期,但随着土壤条件的不断改善,有向阔叶群落演替的趋势。  相似文献   

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耐热性毛霉菌株的筛选,鉴定及生理特性观测   总被引:1,自引:0,他引:1  
从湖北、河南等地收集、分离的61株霉菌中,筛选得到一株可发酵生产腐乳的耐热性霉菌-H4菌株。经鉴定,H4菌株为毛霉(Mucorsp.)。在35℃条件下,该菌株在豆腐坯上生长、发酵良好,为目前报道的最耐热的腐乳生产用菌种之一。  相似文献   

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利用集团分离分析法(Bulked segregant analysis BSA),以辣椒细胞质雄性不育系BU-12、恢复系RF-12为材料共筛选了336条RAPD引物,其中引物S418在恢复系中呈现特异性扩增,得到一条约3000bp的特异片段。回扩得到两条片段,测序表明大小为1515bp,1162bp。荧光原位杂交证实1515bp片段为恢复系特有,命名为S418_(1515)。序列分析表明S418_(1515)为一新发现的序列,Blastn序列比对同源性小于40%,tBlastx比对发现该序列与水稻2、4、7、10号染色体的几个BAC克隆上的序列高度同源。推测可能与其具有相似的编码功能,为进一步从分子水平研究辣椒育性恢复打下了坚实的基础。根据测序结果设计特异引物,将S418_(1515)转化成特异PCR标记,证明能用于候选材料的初筛。  相似文献   

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增强UV-B辐射对小麦叶中CAT、POX和SOD活性的影响   总被引:9,自引:2,他引:9  
研究了0(CK),8.82kJ/m^2(T1)及12.6kJ/m^2(T2)三种剂量的紫外线B(UV-B,280~320nm)辐射对温室种植的小麦膜伤害的机理,试验结果表明,在增强UV-B辐射下,与对照相比,膜脂过氧化物产-丙二醛(MDA)含量明显升高,同时膜脂脂肪酸组成配比改变,不饱和度指数(IUFA)有所下降,并具剂量效应,过氧化氢酶(CAT),过氧化物酶(POX)活性显著升高,而超氧歧化酶(  相似文献   

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