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1.
管理野生罗布麻是利用罗布麻的关键。1963年至1964年在西安草滩农场进行野生罗布麻管理的研究。管理后的罗布麻和自然生长的罗布麻相比,生命条件发生了变化。由于施肥,中耕,防病等项措施,罗布麻密度,株间小气候。耕层养分和盐分产生差异,直接影响到病害程度和植株生长速度,以致产量的质量不同。综合措施,中耕除草,自然保护和耕翻4项试验表明,耕翻是管理野和罗布麻经济而有效的措施。耕翻后野生罗布麻生长期间在密度,生长速度,病害,地上部产量及纤维重量等方面皆表现优越。  相似文献   

2.
我国棉花抗枯黄萎病品种纤维品质遗传改良评价   总被引:6,自引:1,他引:5  
对我国108个抗枯、黄萎病骨干品种的纤维品质进行了分析,整体表现纤维较长,27mm以下的品种较少;比强度平均值较低,但也有少数高强力品种;马克隆值较大,纤维较粗.20世纪60-90年代抗病育种对纤维品质未明显改进,纤维长度、比强度、马克隆值平均值均无显著增长;但纤维长度类型更加丰富,纤维长度最大值有所增加,最高强力品种的比强度值逐渐提高,90年代品种中有较细纤维类型.从中筛选出纤维长度在33mm以上,比强度在33.2cN/tex以上,纤维整齐度在87.1%以上,马克隆值在3.8~4.3之间的品种各10个,筛选出纤维品质指标综合优良的品种9个.  相似文献   

3.
水稻主茎与分蘖间的物质运输   总被引:1,自引:0,他引:1  
本试验借助放射性同位素C~(14)、P~(32)从地上部和地下部分研究了水稻各生育期(分蘖期、抽穗期、乳熟期) 主茎与分蘖间同化物运转的规律,所得结果如下: 1.水稻植株在不同生育期主茎与分蘖间同化物的运转各有特点,分蘖期主茎叶片的同化物和根部吸收的P~(32)均可流向分蘖内,抽穗至乳熟期同化物极少(几乎没有)流入分蘖。分蘖中的物质在分蘖期亦流入主茎;抽穗期同化物则极少流入主茎,乳熟期光合产物流入主茎的量显著增加。 2.分蘖期主茎叶片光合产物流入分蘖的量比分蘖流入主茎的量多16.47%;主茎根系所吸收的P~(32)流入分蘖的量比分蘖流入主茎的量少12.87%。主茎与分蘖地上部与地下部物质相互运转差别直到抽穗期物质相互运转极少的情况下仍然存在。 3.主茎与分蘖间同化物运转与植株各生育期光合产物的积累,各器官对物质的需要,养分(C~(14),P~(32))进入植株体内的途径不同有着密切关系,有自主性,也有相关性。 4.试验征明:水稻植株内养分能互相协调成一个完整的有机联系,看来分蘖植株对水稻体内营养物质有调节的良好影响。特别应当指出的是乳熟期分蘖植株竟有1/3的光合产物转向主茎穗部积极参与主茎结实器官形成,这无疑地对增加主穗重起着有利作用。  相似文献   

4.
罗布麻茎的生长发育与经济价值有密切关系,本文阐述不同地区罗布麻引入陕西后,主茎与分枝的生长表现及一些影响茎部生长的有关因素。1供试材料试验选用连续观察记录较全的地区类型58份,其中:新疆白麻22份、红麻11份;甘肃白麻1份、红麻3份;吉林红麻1份、辽...  相似文献   

5.
山东罗布麻的分布及开发利用   总被引:8,自引:1,他引:7  
罗布麻是一种野生高级纤维植物,经济价值很高.山东是罗布麻的天然产地,有丰富的罗布麻资源.然而大量的宝贵资源未被开发利用.罗布麻适宜生长在盐碱沙荒地,山东省有大面积的盐碱沙荒地,保护和开发利用罗布麻资源前景广阔.  相似文献   

6.
罗布麻(Apocynum venetum L.)突变体的获得是人工创新种质资源的有效途径,也是开展品种选育、功能基因组研究的基础。本研究以采自东营野生罗布麻种子作为材料,预试验结果表明0.7%的甲基磺酸乙酯(EMS,ethylmethylsulfone)溶液诱变罗布麻种子13 h能够达到半致死剂量。在此浓度和处理时间下构建了一个1452株的突变体群体,对获得的M1植株进行农艺性状和总黄酮含量性状筛选,初步获得125份农艺性状突变材料,其中包括8株白化植株、23株叶型变异株、16株叶色黄纹突变体、32株苗期分枝植株以及46株叶位变异突变体,突变频率分别为0.55%、1.6%、1.1%、2.2%和3.2%。此外,还筛选到2株总黄酮含量明显高于野生型和1株低于野生型的材料。在突变群体中对黄酮代谢途径中编码黄烷酮-3-羟化酶的基因(F3H,flavanone 3-hydroxylase gene)进行测序鉴定,结果鉴定到3株F3H基因的突变体。本研究构建的罗布麻突变体库表型丰富且突变位点可以鉴定,是罗布麻新种质筛选、品种选育以及基因功能研究的良好材料。  相似文献   

7.
罗布麻花朵繁多、有蜜腺、花期相当长,使该植物除医药、纤维用途外,又可能作为蜜源植物。本文观察分析罗布麻地区类型引入陕西后的现蕾、开花期等发育方面的表现。1供试材料罗布麻地区类型93份,计来源于10个省区,其中新疆白麻36份(包括种子16份、原产地根茎...  相似文献   

8.
从罗布麻植物生长特点和纤维利用出发,建议我国罗布麻使用“罗布红麻”和“罗布白麻”以区别罗布麻的2个有生产意义的种。  相似文献   

9.
安徽短萼黄连种群特性及其濒危机制探讨   总被引:4,自引:1,他引:3  
张莉  张小平 《应用生态学报》2005,16(8):1394-1398
对安徽省境内短萼黄连的地理分布、分布地自然概况及种群大小、分布格局、年龄结构等种群特性进行研究.结果表明,短萼黄连在安徽省主要分布于九华山、黄山、清凉峰和牯牛降等山区.其生境涉及林冠下和水沟边两种类型,均表现为阴湿、土壤疏松、呈酸性而富含有机质,要求光照荫蔽度平均达到70%以上,空气相对湿度70%~90%,土壤含水量在30%以上.现有短萼黄连种群均为高群集分布,年龄结构不合理,且多为小种群,表明种群已处于相对不稳定阶段.自然生境的严重破坏、成年植株的过度采挖对短萼黄连种群的生存构成严重威胁,是造成部分野生种群个体数量急剧减少的主要原因.  相似文献   

10.
高盐胁迫对罗布麻生长及离子平衡的影响   总被引:18,自引:2,他引:16  
采用网室盆栽试验,研究了不同浓度NaCl(100~400mmol.L-1)胁迫30d对罗布麻植株生物量积累、生长速率、根系活力、盐分和矿质离子吸收、分布等的影响.结果表明:100mmol.L-1NaCl处理30d,罗布麻植株鲜质量和生长速率显著下降,但对其干质量没有影响;随着盐度的增加,罗布麻植株干质量、鲜质量和生长速率均显著降低.100~200mmol.L-1NaCl胁迫下,罗布麻根系活力明显高于对照;300~400mmol.L-1NaCl盐胁迫下,其活力显著降低.随着盐浓度的增加,罗布麻根、茎和叶片Na+含量逐渐增加、K+含量缓慢降低;叶片Ca2+、Mg2+含量明显降低,茎部Ca2+和根部Mg2+含量有不同程度的增加.盐胁迫明显降低了罗布麻根、茎和叶片K+/Na+、Ca2+/Na+和Mg2+/Na+的比率,植株选择性吸收和运输K+、Ca2+的能力显著提高.罗布麻植株很强的拒盐能力,以及对K+、Ca2+的选择性吸收和运输是其具有高盐适应性的主要原因.  相似文献   

11.
利用粗线期染色体和DNA纤维的荧光原位杂交(FISH)技术分析了水稻广陆矮四号(Oryzasativassp.indicacv.GuangluaiNo.4)的端粒序列。粗线期染色体荧光原位杂交结果表明,大多数染色体的末端都有端粒串联重复,但信号的强度在不同染色体上是不同的。伸展DNA纤维荧光原位杂交结果显示,端粒最长的线状信号长度为6.55μm,最短的为1.82μm,依据2.51kb/μm的标准,它们分别相当于16.44kb和4.56kb。端粒的平均信号长度为3.62±1.32μm,相当于9.09±3.31kb。由此可以估计,最长的、最短的和平均长度的端粒拷贝数约为2349、651和1298±473。  相似文献   

12.
二倍体石蒜在安徽发现   总被引:15,自引:2,他引:13  
本文以根尖细胞为材料,观察了石蒜Lycoris radiata(L′Her.)Herb.三个不同居群植物的染色体数目和核型,发现石蒜为一复合体,包括两种不同类型:(1)三倍体类型,主要包括一群以鳞茎无性繁殖的园艺栽培植株,其染色体数目和核型为2n=33=33t(st),属“4A”核型,且极其稳定。(2)二倍体类型,主要包括一群野生植株,变异较大,我们发现有下列几种情况:一是芜湖产石蒜(L.radiata)的野生材料,其染色体数目和核型为2n=21+1B=1m+12st+8t+1B,属“3A”核型,在石蒜种内迄今未见有类似报道;另一是黄山产野生材料,观察到两个细胞型,绝大多数细胞为2n=22=12st+1Ot,极个别细胞出现2n=22+1B=6st+14t+2T+1B的情况,均属“4A”核型。芜湖和黄山野生材料的染色体数目和核型均为首次报道。石蒜(L.radiata)的二倍体类群也是首次在安徽发现。  相似文献   

13.
Food-chain length is a central characteristic of ecological communities that affects community structure and ecosystem function. What determines the length of food chains is not well resolved for most ecosystems. Herein, we examine environmental correlates of food-chain length based on the productivity hypothesis, compare food-chain lengths among aquatic ecosystem types and identify bi-directional effects of river impoundment on food-chain length in the Paraná River Basin of South America. Both temperature regime, a surrogate of productivity, and ecosystem type significantly affected food-chain length in independent analyses. However, when analyzed together, only ecosystem type explained significant variation in food-chain length. Food chains were longest in reservoirs, and shortest in high-gradient rivers. The proximate mechanism driving this pattern appears to be body-size ratios of primary consumers to apex predators, which differ among trophic pathways. Food chains based on phytoplankton production may have an additional size-structured link not present in food chains based on other basal sources such as detritus and algae. Hydrogeomorphology is the ultimate mechanism influencing food-chain length because it affects the relative importance of basal carbon sources supporting higher trophic levels, which through differences in the number of trophic links along the different size-structured pathways, appears to drive the observed patterns in food-chain length. We discuss a hypothesis of food-chain length that integrates energy flow and size-structure, facilitates inclusion of temporal dynamics and which is readily testable in both 'closed' and 'open' ecosystems.  相似文献   

14.
盾叶薯蓣环阿屯醇合酶全长基因的克隆与分析   总被引:1,自引:1,他引:0  
环阿屯醇合酶(cycloartenol synthase,CAS)是薯蓣皂甙元生物合成途径中的第一个关键酶.以基因组DNA为模板,利用染色体步行和长距离PCR方法首次克隆了盾叶薯蓣CAS全长基因.序列分析比较结果表明,盾叶薯蓣CAS全长基因为7 192 bp,由18个外显子和17个内含子组成.外显子总长为2 280 bp,编码759个氨基酸,最长的外显子为198 bp,最短的为47 bp;内含子总长4 912 bp,最长的内含子为1 551 bp,最短的为68 bp.Southern blot杂交分析表明,CAS基因在盾叶薯蓣基因组中为单拷贝.  相似文献   

15.
Telomeres play a role in cellular aging and they may also contribute to the genetic basis of human aging and longevity. A gradual loss of the telomeric repeat sequences has been reported in adult tissue specimens. This study determined the percentage of telomere restriction fragment in various molecular-sized regions in addition to measuring the average telomere length. Mean telomere restriction fragment (TRF) length was determined by Southern blot analysis using a longer telomeric repeat probe with higher sensitivity. A significant decrease in longer telomere fragments and a quick increase in the shortest fragments were observed, especially in male subjects. There was a tendency that the age-adjusted telomere length was longer in females than that observed in males, while males lose the telomeric sequence faster than females. These data indicated that the percentage of longer telomeres fragments decreased, while the shortest fragments increased quickly with age. In addition, the longest telomere fragments decreased and the short fragments increased with a relatively stable frequency with age. There was also a significant difference in the longest telomere fragment percentage between males and female in their 40s and 50s, whereas no difference was observed in the mean TRF length. Interestingly, the changing rate of the longest and the shortest range group of TRF percentage associated with aging seemed quite different between before and after 50-year old with a gender-related contrast. This contrast implies a drastic change around the age of 50 of unknown factors that affect telomere attrition. The first two authors equally contributed to this article.  相似文献   

16.
对五爪金龙(Ipomoea cairica (Linn.) Sweet)进行切割试验,对其在不同光环境及不同季节的萌芽率、成活率、主茎长度和生物量等进行研究。结果表明:五爪金龙切条越短其萌芽越迟,其成活率、主茎长度和生物量下降;五爪金龙在光下和林下的成活率无显著差异,但林下生物量较低;切条越短,林下条件越不利于主茎的伸长;冬季五爪金龙的主茎长度和生物量最低;夏季在光下和林下不能再生的最长切条长度均为4 cm;秋季均为1 cm;而冬季光下为1 cm,林下为3 cm;春季光下则为4 cm,林下为5 cm。春季时将五爪金龙切割为5 cm并置于林下是最经济的防除方法;如果不考虑季节性及光条件,应将其切割至1 cm以下的片段,可以有效防止五爪金龙再生。  相似文献   

17.
加拿大一枝黄花的核型分析及B染色体初报   总被引:7,自引:0,他引:7  
对安徽蚌埠地区外来植物加拿大一枝黄花的染色体核型进行了分析。结果如下:该入侵种的染色体数为2n=50,各染色体间形态差异不明显,均为中着丝粒或近中着丝粒染色体,最长与最短染色体相对长度比为1.72,全套染色体未见随体,核型公式为2 n=50=38 m 12 sm 6 B s,核型类型为较对称的2A型。首次报道了存在于体细胞中的异于常染色体的6个B染色体,这些B染色体在不同细胞中保持恒定的数目,并讨论了B染色体的存在与加拿大一枝黄花在新生境中具有入侵性之间的关系。  相似文献   

18.
ABSTRACT. The internal transcribed spacer (ITS) between the mitochondrial large (23S rRNA; rnl ) and small (16S rRNA; rns ) subunit ribosomal RNA genes of Acanthamoeba castellanii strain Neff was sequenced previously and was uniquely interesting because it contained tRNA genes with acceptor stem mismatches that underwent RNA editing repair. Our interest in this ITS region was to determine its phylogenetic potential in differentiating between closely related isolates. We analyzed the mitochondrial ITS region for 17 Acanthamoeba isolates and observed extensive sequence and length variability, making this region difficult to align. Acanthamoeba griffini strain S-7 had the shortest ITS (i.e. 559 base pairs [bp]) compared with Acanthamoeba palestinensis strain Reich, which had the longest (i.e. 1,360 bp). The length disparity occurred predominantly between the spacer region of the aspartic acid ( trnD ) and methionine ( trnM ) tRNA genes. Unexpectedly, this region in A. palestinensis Reich was found to contain a duplication of the trnM gene. Additionally, like A. castellanii strain Neff, all isolates examined had tRNAs with mismatches in their acceptor stem. Also, the potential for an additional type of editing not described previously for Acanthamoeba , involving purine to pyrimidine transversions was observed.  相似文献   

19.
Reproduction in yellowtail snapper Lutjanus argentiventris took place after compressing the seasonally changing day length into a 3 month period applied during two consecutive winters, with the longest and shortest days in December and February, respectively. During the first winter, there was no clear peak of days of spawning and the production of viable eggs was similar from the longest and throughout the decreasing day lengths until reproduction ceased. The level of plasma vitellogenin rose abruptly to a maximum concentration during the increasing day length and then decreased dramatically before the longest day length. During the second winter, a clear peak in the number of days of spawning and the highest production of viable eggs occurred around the longest day length. These results showed that it is feasible to synchronize day length between winter-induced and natural summer and autumn reproduction to produce eggs and larvae during the year.  相似文献   

20.
杨志荣  林祁 《植物研究》2007,27(6):661-663
采用常规制片方法首次对铁箍散(Schisandra propinqua(Wall.)Baill.)做了核型分析,结果表明铁箍散体细胞染色体数目为2n=28,核型公式为2n=2x=20m+8sm,染色体相对长度组成2n=28=2L+14M2+8M1+4S,染色体长度比为2.14,核型类型为2B型,核型不对称系数0.59,无次缢痕和随体。铁箍散的核型特点表明其在五味子属中处于较进化的地位。  相似文献   

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