降低魔芋球茎组培褐变的技术研究

以魔芋球茎为外植体,研究组织培养过程中有效降低外植体褐变的方法。采用MS+6-BA 1 mg/L+NAA 1 mg/L为基本培养基,用正交实验方法研究不同琼脂浓度、吸附剂及光、暗2种不同培养条件下,对魔芋组织培养过程中褐变的影响。在MS+6-BA 1 mg/L+NAA 1 mg/L+蔗糖30 g/L+琼脂 6 g/L+AC 0.5 g/L+PVP 0.05 g/L及暗培养条件下,魔芋外植体的褐变率减低为38.3%,愈伤组织诱导率提高到78.3%。在培养基中加入一定量的活性炭(AC)和聚乙烯吡咯烷酮(PVP),并进行暗培养,可在一定程度上控制魔芋外植体的褐变,促进愈伤组织形成。     

金毛狗脊原叶体增殖和孢子体转化条件的优化

为探究不同浓度的无机盐、蔗糖、KT、NAA和6-BA等对金毛狗脊原叶体增殖和孢子体转化的影响，采用正交设计实验方法，设置5因素4水平正交试验，筛选金毛狗脊原叶体增殖和孢子体转化的最佳培养基。结果表明，原叶体增殖最佳培养基为1/2MS+2%蔗糖+0.1 mg/L NAA+0.3 mg/L 6-BA+0.1 mg/L KT。孢子体转化最佳培养基为1/4MS+1%蔗糖+0.5 mg/L KT+0.1 mg/L NAA。     

非洲菊组织培养基筛选研究

采用不同的培养基配方对非洲菊花托进行组织培养试验,综合分析不同的培养基配方在非洲菊组培过程中对花托培养、继代增殖和壮苗生根的影响。结果表明在试验配方中非洲菊花托培养的最适组织培养基为MS+6BA10mg/L+NAA1.0mg/L+糖30g/L+琼脂5%;继代增殖培养的最适组织培养基为MS+6BA1.0mg/L+NAA0.2mg/L+糖30g/L+琼脂7%;无根苗壮苗生根的最适组织培养基均为1/2MS+NAA0.5mg/L+糖20g/L+琼脂7%。     

宁夏主栽水稻品种高频再生体系的建立

通过对宁夏多个主栽水稻品种愈伤组织的培养,结果表明,诱导水稻愈伤组织的最适培养基是:N6+2mg/L 2,4-D+0.5/L水解酪蛋白+0.5g/L L-脯氨酸+8g/L琼脂+30g/L蔗糖;水稻愈伤组织最适分化培养基是:MS+2mg/L 6-BA+0.5mg/L NAA;水稻的最适生根培养基为:MS+0.5mg/L NAA.筛选出了诱导愈伤组织和愈伤组织分化的最适激素浓度配比和最适分化条件.     

红花文殊兰的离体培养及快速繁殖

以红花文殊兰的鳞茎为外植体,研究不同培养基对其腋芽启动、不定芽增殖及生根培养的影响。研究表明,腋芽启动的最适培养基为5.0 mg/L MS+6-BA+0.2 mg/L NAA+活性炭1 g/L,腋芽的诱导萌发率为88%;不定芽增殖的最适培养基为MS+2.0 mg/L 6-BA+0.5 mg/L TDZ+0.1 mg/L NAA+活性炭0.5 g/L,40 d的增殖系数可达7.16;壮苗培养基为1/2 MS+0.5 mg/L 6-BA+0.1 mg/L NAA+10%椰子水(CW)+活性炭0.5 g/L;生根的最适培养基为MS+0.5 mg/L NAA+0.5 mg/L IBA+活性炭0.5 g/L,生根率达100%,根系发达,植株生长健壮。生根苗经一段时间炼苗后,移栽到基质为树皮∶椰糠∶河砂=1∶1∶1的苗钵上,红花文殊兰的假植成活率达95%。该研究建立了红花文殊兰的快繁体系,为其工厂化生产提供技术支持。     

两种观赏水草的离体培养

本试验以两种观赏水草为供试材料,进行离体培养研究。试验结果表明：红波（Alternanthera bettzickiana）以叶片为外植体,愈伤组织诱导采用MS+6-BA0.5 mg/L (单位下同)+NAA0.2的培养基,芽诱导采用MS+6-BA2.0 +NAA0.05+AD10的培养基,茎尖芽诱导采用MS+6-BA2.0+NAA0.05培养基,继代培养采用MS+6-BA1.0 +NAA0.05的培养基,根诱导采用1/2MS+IBA0.5的培养基;金钱草（Lysima chiachristinae Hance）以茎尖为外植体,芽诱导采用MS+6-BA0.5+NAA0.02的培养基,继代培养用MS+6-BA0.5+NAA0.05的培养基,根诱导采用1/2MS+IBA0.5的培养基,上述培养基中均含有30 g/L蔗糖和6g/L琼脂,PH5.6,在培养温度25℃、光照强度1800Lx、光照时间12h/d的培养条件下,均能培育出完整植株。     

切花月季卡罗拉组培与快繁研究——基本外植体和初代培养基筛选

以切花月季卡罗拉茎尖、茎段、叶片、花蕾为试验材料,对卡罗拉进行了初代培养研究.结果表明:茎段比茎尖更适合作为芽诱导培养材料;基本培养基以1/2MS为宜,适合芽诱导培养基配方为1/2 MS +6-BAl.5mg/L+ NAA0.5mg/L或1/2 MS+ZT l.5 mg/L+ NAA 0.5 mg/L,芽诱导率在80%以上.     

连香树胚性细胞悬浮系的建立和植株再生

本试验以连香树授粉120 d后未成熟种子子叶胚为外植体,开展胚性愈伤诱导增殖和悬浮培养体系的研究,初步建立了连香树胚性细胞悬浮系与植株再生体系。将连香树未成熟子叶胚接种在添加0.5 mg/L6-BA+1.0 mg/L NAA+1.0 g/L AC的1/2 MS基本培养基上,进行胚性愈伤组织诱导,获得的愈伤组织在0.1 mg/L 6-BA+0.1 mg/L NAA+0.5 g/L AC的1/2 MS固体培养基上进一步增殖培养。将得到的胚性愈伤组织置于添加5%聚乙二醇6000的1/2 MS的悬浮培养液中进行振荡培养,建立起细胞均一、增殖较快、稳定性较强的细胞悬浮系;将悬浮培养获得的胚性材料接种到添加5%香蕉汁的0.1 mg/L 6-BA+0.1 mg/L NAA+0.5 g/L AC的MS固体培养基中进行培养,可分化出的子叶期体胚,将获得的子叶胚转接到添加1.0 mg/L IBA的WPM固体培养基中,体胚萌发再生成植株。     

紫甘薯组织培养快繁技术研究

将紫甘薯的茎段或茎尖作为外植体,培养在添加各种激素配比的培养基上,研究紫甘薯组培快繁影响因素,筛选培养所需最佳初代、增殖和生根的培养基及培养条件。结果表明：在外植体分化时的初代培养基MS+BA 2.0 mg/L,增殖培养基最佳配方为MS+ BA 1.0 mg/L+ NAA 0.1~0.2 mg/L,适合生根的培养基为1/2MS+ NAA 0.1 mg/L+ IAA 0.1 mg/L。     

铁皮石斛组织培养及快繁技术研究

为建立铁皮石斛快繁技术体系,给生产提供参考,研究了铁皮石斛组织培养过程中的灭菌方法、腋芽诱导、原球茎的诱导、增殖与分化的最佳培养基配方。以铁皮石斛成熟茎段为外植体,探讨1/2MS培养基或MS培养基中添加不同浓度的激素对铁皮石斛组织培养过程中各生长、分化阶段的影响。研究表明,腋芽诱导最适宜培养基的配方为MS+ 6-BA 2.0 mg/L+ NAA 0.5 mg/L,诱导率达91.28%,平均芽数达2.34;原球茎诱导的最适宜培养基为1/2MS+ 6-BA 0.5 mg/L+NAA 0.5 mg/L+2,4-D 1.0 mg/L,诱导率可达66.67%;原球茎增殖最佳培养基为1/2MS+ 6-BA 3.0 mg/L+NAA 0.3 mg/L,原球茎分化最适宜培养基为1/2MS+ NAA 1.0 mg/L+ 6-BA 3.0 mg/L+ KT 1.0 mg/L,最适宜生根的培养基配方为1/2MS+NAA 2.0 mg/L+ AC 0.5 g/L。     

Cytology of Phleum sp. affin. P. montanum C. Koch

Diploid, tetraploid, and hexaploid plants occurred in foreign plant introductions of P. sp. affin. P. montanum from Turkey and Iran. Within-progeny variations in polyploid levels indicate that divergent races occurred as interspersed but natural populations. One to six B-chromosomes of varying sizes in addition to the normal chromosome complement were present in some plants. Their behaviours appeared essentially similar to those recorded for other species. Certain of the plants examined exhibited cytological features similar to those observed in known hybrids. These included prophase pycnosis, stickiness, split metaphase I plates, unoriented chromosomes at M-1, and low levels of pollen stainability. These features were absent in microsporocytes of other plants. Low open-pollination seed set characterized all plants examined. This may be due to hybridity or possibly to response to ecological conditions of the new environment.Results of co-operative work of the Crops Research Division, A.R.S., U.S. Department of Agriculture, and the Wisconsin Agricultural Experiment Station, Madison, Wisconsin.Former Graduate Student, Department of Agronomy, Wisconsin Agricultural Experiment Station, and Geneticist, Crops Research Division, Agricultural Research Service, U.S. Department of Agriculture.     

U.S. Economic Growth vs. Environmental Conditions

A widely-held belief is that stricter environmental regulations stifle economic growth. To determine empirically the effect of environmental conditions and policies on state-level per capita income growth, a Barro-type economic growth model was estimated for the years 1982 to 1991, which correspond to two consecutive troughs in the business cycle. States with better environmental conditions had significantly higher income growth rates during this period. At the same time, stricter environmental policies did not significantly depress income growth. Data used include recently developed, consistent measures of environmental policy and quality for individual states, as well as data from the 1980 U.S. Census and Bureau of Economic Analysis.