亚麻优异种质创新利用及发展

亚麻种质创新工作采用外源总体 DNA导入 ,Co6 0— γ射线处理种子、植株以及利用雄性核不育材料进入转育等方法创造新类型、新材料 ,提供给育种家 ,培育出一批优异亚麻新品种 ,促进了亚麻生产的飞速发展。随着新的生物技术和信息技术的突破 ,对今后种质创新工作进行展望     

我国亚麻种质资源研究与利用概述

亚麻是重要的多用途作物,其综合利用价值非常高,我国是亚麻加工和产品出口大国,随着亚麻生产的发展,对优异亚麻资源的需求越来越大,亚麻种质的研究和利用已成为推动亚麻产业发展的重要因素。本文分别从亚麻种质资源的种类及分布、我国亚麻种质资源收集与保存、鉴定与评价、利用与创新等方面进行综述,并提出了现有研究的不足和建议,以期为促进我国亚麻种质资源创新和亚麻属作物的研究提供参考。     

亚麻优异种质创新利用及发展

亚麻种质创新工作采用外源总体DNA导入，Co60-γ射线处理种子，植株以及利用雄性核不育材料进入转育等方法创造新类型，新材料，提供给育种家，培育出一批优异亚麻新品种，促进了亚麻生产的飞速发展，随着新的生物技术和信息技术的突破，对今后种质创新工作进行展望。     

麻类优异种质的创新与利用研究

作物种质资源是育种和生产重要的物质基础,种质创新是种质资源研究的核心.通过多年的系统研究,我国麻类种质资源研究已跃居世界先进水平,成为世界麻类资源大国.但是,麻类种质创新落后、育种材料遗传基础狭窄、可利用资源贫乏的矛盾还十分突出,种质资源研究与育种和生产还有较大的差距.本文报告了麻类种质创新的方法和技术,麻类优异基因源的发掘和利用,"十五"苎麻、红麻、亚麻、黄麻优异种质创新和利用的成果,对今后的麻类种质创新工作提出了一些设想和建设性建议.     

多胚亚麻种质的研究与利用

本文对多胚亚麻种质资源的引进、保存、遗传、诱导及多胚苗的形态学、细胞学、分子生物学和种质创新利用等进行了深入的研究与探讨.选出株高、纤维含量及多胚率等表现不同的株系19个,创制多胚种质115份,本研究对亚麻种质多胚性保持、提高及利用具有一定意义,同时,还对多胚亚麻育种存在问题提出了建议.     

我国亚麻种质资源的研究与评价利用

本文介绍了我国亚麻生产、种质资源的分布特点、生态类型、搜集保存、鉴定评价以及种质资源的利用创新成果.     

“十五——十一五”黑亚系列优异创新种质简介

亚麻种质资源是育种和生产发展的基础,亚麻育种的突破性进展与优异种质源的发现和利用密切相关。自“六五”以来,黑龙江省农业科学院经济作物研究所一直是亚麻种质资源收集、保存和利用项目的主持单位,经过连续几个“五年”攻关计划、平台建设项目的实施,国内优异种质资源筛选、鉴定、评价和创新利用等方面均取得了重要进展,为亚麻生产发展提供了物质基础。但在亚麻品种改良体系中,优异新种质的创造与利用之间往往呈现出滞后现象,     

我国亚麻种质资源的研究与评价利用

本文介绍了我国亚麻生产、种质资源的分布特点、生态类型、搜集保存、鉴定评价以及种质资源的利用创新成果。     

麻类优异种质的创新与利用研究

作物种质资源是育种和生产重要的物质基础，种质创新是种质资源研究的核心。通过多年的系统研究，我国麻类种质资源研究已跃居世界先进水平，成为世界麻类资源大国。但是，麻类种质创新落后、育种材料遗传基础狭窄、可利用资源贫乏的矛盾还十分突出，种质资源研究与育种和生产还有较大的差距。本文报告了麻类种质创新的方法和技术，麻类优异基因源的发掘和利用，“十五”苎麻、红麻、亚麻、黄麻优异种质创新和利用的成果，对今后的麻类种质创新工作提出了一些设想和建设性建议。     

麻类种质资源的收集、保存、更新与利用

本文报道了我国麻类种质资源的考察收集、安全保存和优异种质的评价利用现状,讨论了黄麻、红麻、亚麻、大麻种质资源的繁种更新技术关键和经验, 并对麻类种质资源工作的发展提出了一些设想和建设性建议 .     

咸宁苎麻产业形势与发展对策

本文阐述了咸宁苎麻产业经营的现状,发展的有利条件,制约因素和进一步发展苎麻产业的构思,以及实现这一构思采取的几项举措:扩大生产规模;加强优质原料基地及龙头企业的建设;提高品牌档次,促进工业带动农业,集科、工、农、贸为一体,走产业经营的发展道路.     

大豆DNA扩增片段长度多态性(AFLP)研究

本文研究ＡＦＬＰ技术在大豆上的应用,在改进大豆种子ＤＮＡ提取方法的基础上,比较同位素与银染检测方法的效果,筛选适宜大于大豆ＡＦＬＰ分析的酶切和引物组合,从而建立了适用于大豆指纹图谱快速鉴定的ＡＦＬＰ操作程序,并对我国野生大豆和栽培大豆代表性材料进行了ＡＦＬＰ分析。     

稻田土壤杂草种子库研究

对江苏省仪征市连年稻麦两熟轮作稻田土壤杂草种子库中杂草种类进行了考查。结果表明, 有11 科22 种杂草的种子主要分布在0～10 cm 土层内。同时, 阐述了土壤种子库杂草种子的来源, 因水分、湿度、光照等自然因素和耕作、人工除草等人为因素, 杂草种子本身的完熟度等综合因素造成了土壤杂草种子库中杂草种子活力的损失与累积, 以及杂草种子萌发与土层深度、水分等的关系, 初步探明了水旱轮作对稻田土壤杂草种子库的影响, 提出了减少杂草种子库种源的对策。     

R5期遮荫对大豆植株体内源激素和酶活性的影响

在Ｒ５期利用人为每天遮荫８小时,连续遮荫１０天,研究了遮荫对生殖生长期大豆叶片蔗糖合成酶（ＳＳ）,蔗糖磷酸合成酶（ＳＰＳ）,谷氨酸合成酶（ＧＳ）活性及叶片和子粒中的四种内源激素含量的影响,结果表明：遮荫明显增加叶片的三种酶活性,提高子粒中ｉＰＡ,ＧＡ和ＡＢＡ的含量,改变叶片中ＧＡ,ｉＰＡ和ＩＡＡ的积累方式。认为酶活性及内源激素的变化是大豆忍耐遮荫不良环境积极生理反应,有助于减少产量和品质损失。     

水稻植株防御白背飞虱为害的某些生理反应

 以对白背飞虱具有不同抗性水平的水稻品种(组合) 为材料, 研究了水稻在白背飞虱为害后稻株体内的生理变化。结果表明, 稻株受害后, 感虫品种(TN1和汕优63) 光合作用速率和叶绿素含量下降比抗虫品种(N 22) 明显; 感虫品种超氧化物歧化酶(SOD) 活性增加, 过氧化物酶(POD) 和过氧化氢酶(CAT) 活性下降, 而抗虫品种POD 和SOD 均增加, CAT减少;感虫品种除丙氨酸含量下降外, 其他氨基酸含量均上升, 尤其是天门冬氨酸、苏氨酸、缬氨酸及蛋氨酸等含量增加很快, 抗虫品种中天门冬氨酸、缬氨酸等含量增加也很快, 但苏氨酸、蛋氨酸、丙氨酸的含量显著下降。     

水稻田表水磷素的动态特征及其潜在环境效应的研究

通过独立排灌式磷肥大田试验探讨了水稻田表水磷素的动态特征及其潜在的环境效应。研究发现, 施入磷肥增加了田表水磷素水平, 首次水样总磷水平为0.201～ 1.301 mg/kg, 溶解磷水平为0.058～ 0.926 mg/kg; 在等量施磷的条件下, 与单施无机磷肥比较, 有机无机磷配施能显著地提高田表水磷素水平; 在首次采样的一周之内, 两者总磷水平相差达3.85～1.89 倍, 但随着时间的推移, 因施磷结构的不同导致田表水磷素水平的差异逐渐缩小并趋于一致。任一次田间排水都存在诱发附近水域水体富营养化的可能。从减少磷素流失的角度出发, 在施磷灌水后约一周之内或田间耘田时, 田间排水磷素流失潜能增大, 另外, 还要避免在雨水集中的季节施用磷肥。     

An in planta, Agrobacterium-mediated transient gene expression method for inducing gene silencing in rice (Oryza sativa L.) leaves

Background

Although the genetic structure of rice germplasm has been characterized worldwide, few studies investigated germplasm from Thailand, the world’s largest exporter of rice. Thailand and the International Rice Research Institute (IRRI) have diverse collections of rice germplasm, which could be used to develop breeding lines with desirable traits. This study aimed to investigate the level of genetic diversity and structures of Thai and selected IRRI germplasm. Understanding the genetic structure and relationships among these germplasm will be useful for parent selection used in rice breeding programs.

Results

From the 98 InDel markers tested for single copy and polymorphism, 19 markers were used to evaluate 43 Thai and 57 IRRI germplasm, including improved cultivars, breeding lines, landraces, and 5 other Oryza species. The Thai accessions were selected from all rice ecologies such as irrigated, deep water, upland, and rainfed lowland ecosystems. The IRRI accessions were groups of germplasm having agronomic desirable traits, including temperature-sensitive genetic male sterility (TGMS), new plant type, early flowering, and biotic and abiotic stress resistances. Most of the InDel markers were genes with diverse functions. These markers produced the total of 127 alleles for all loci, with a mean of 6.68 alleles per locus, and a mean Polymorphic Information Content (PIC) of 0.440. Genetic diversity of Thai rice were 0.3665, 0.4479 and 0.3972 for improved cultivars, breeding lines, and landraces, respectively, while genetic diversity of IRRI improved and breeding lines were 0.3272 and 0.2970, respectively. Cluster, structure, and differentiation analyses showed six distinct groups: japonica, TGMS, deep-water, IRRI germplasm, Thai landraces and breeding lines, and other Oryza species.

Conclusions

Thai and IRRI germplasm were significantly different. Thus, they can be used to broaden the genetic base and trait improvements. Cluster, structure, and differentiation analyses showed concordant results having six distinct groups, in agreement with their development, and ecologies.     

The Incidence and Effect on Total Tuber Carotenoids of a Recessive Zeaxanthin Epoxidase Allele (<Emphasis Type="Italic">Zep1</Emphasis>) in Yellow-fleshed Potatoes

Zeaxanthin epoxidase (Zep) is one of at least two genes important for the incidence and amount of carotenoids in yellow-fleshed potato. The recessive allele of the gene encoding zeaxanthin epoxidase (Zep1) has previously been shown to inhibit the conversion of the xanthophyll zeaxanthin to other, more polar carotenoids. We examined the effect of the dosage of Zep1 on total carotenoids in yellow-fleshed tetraploid potato germplasm. The dosage of heterozygous individuals was determined using high-resolution DNA melting. We also surveyed a wide range of germplasm available in the USDA-ARS potato breeding program in Washington for the presence and dosage of Zep1. Genotypes with zero, one, or two copies of Zep1 had statistically similar levels of total tuber carotenoids. Triplex individuals showed a small but significant increase in total carotenoids over the previous three classes. In turn, individuals that were homozygous for Zep1 had much higher levels of total carotenoids than all other dosage classes. This suggests that a slight dosage effect is present, but that the effect of Zep1 is indeed largely recessive. A significant amount of variation in total carotenoids was observed within all Zep1 dosage classes, reinforcing the evidence that additional loci are important for high total carotenoids in potato. Our survey of breeding germplasm supported earlier research that Zep1 is uncommon in tetraploid potato germplasm. The use of high-resolution DNA melting again allowed us to identify the dosage of Zep1 in heterozygous individuals. This is important for breeding high-carotenoid potatoes at the tetraploid level, since recovery of homozygous Zep1 individuals is very rare. Identification of agronomically desirable parents with two or more copies of Zep1 would allow for higher recovery of homozygous Zep1 progeny, permitting additional selection for other desirable traits.     

Diploid potato germplasm derived from wild and land race genetic resources

Diploid cultivated species, haploids derived from tetraploid cultivars, and their wildSolanum relatives were used to generate various diploid potato genetic stocks. These stocks have significant value in potato breeding because: 1) genetic diversity in the potato population can be kept variable with the diploid germplasm which confers genetic variation from wild and cultivated species; 2) crossability of this diploid germplasm is facilitated by the function of 2n gametes; and 3) high levels of pest resistances originating from the process of introgression of the wild and cultivated genetic resources can be used to improve the tetraploid cultivated potato genepool.     

Potato genetic resources: Sources of resistance and systematics

The major potato of commerce,Solanum tuberosum L., is the fourth most important food crop in the world after rice, wheat and corn. Fortunately, the potato has many primitive cultivars and wild species relatives useful to reduce our reliance on chemical controls. These include resistances against diseases, pests, and traits for useful agronomic characters such as yield, specific gravity, chipping qualities, and suppression of enzymatic browning. This paper summarizes some of these qualities, and provides an overview of germplasm availability and taxonomy of the wild species. The major potato of commerce,Solanum tuberosum L., is the fourth most important food crop in the world after rice, wheat and maize. It is grown in more countries than any other crop but maize, and forms the staple crop of many societies. Over 280 million metric tons were grown worldwide in 1989, with Eastern Europe growing 46%, Asia 22%, Western Europe 17%, North America 7%, Latin America 5%, and Africa 3% (2). It is the leading vegetable crop in acreage and farm value in the United States, with 1.2 million acres planted in 1991, with a value of sales almost two and one-half billion dollars (53).Solanum tuberosum is one species of a group of seven cultivated and 216 additional tuber-bearing, and nine non-tuber-bearing wild relatives, all classified by Hawkes (41) in the genusSolanum, sectionPetota Dumort The purposes of this paper are threefold: 1) to provide examples of the proven and potential utility of wild and cultivated landrace members of sect.Petota for reducing our reliance on chemical controls for many pests and diseases that affect commercial cultivars, 2) to provide an overview of the status of germplasm availability of these species, and 3) to highlight the benefits for continuing germplasm collections and systematic studies of the group.