中国作物种质资源安全保存理论与实践

我国是作物种质资源大国,目前已经收集保存了340种作物,保存资源总量达50万份,如何确保安全保存是种质资源管理的首要课题。自"九五"以来,系统地开展了作物种质资源安全保存理论与技术的研究,揭示了种质活力丧失存在关键节点及其生物学机制;明确了发芽率低于关键节点后进行更新,会导致群体遗传完整性降低;提出了种质安全保存寿命的概念,以及延长安全保存寿命的关键因素。研发了种质活力监测预警、繁殖更新与离体保存等关键技术,制定了种质资源入库圃保存、监测预警、繁殖更新、离体保存和设施建设等技术规程,创建了中国作物种质资源安全保存技术体系。该体系应用于全国作物种质资源的保存实践,最大程度延长种质安全保存寿命,并监测预警出需更新的种质,避免因活力和遗传完整性丧失而导致种质资源得而复失,为实现我国作物种质资源长久安全保存提供了有力保障。     

《芒属种质资源描述规范和数据标准》的制定

目前芒属植物被视为最有前景的木质纤维素能源作物,在中国、美国、日本和欧洲国家得到了广泛研究和利用。但截至目前依然没有统一的芒属植物种质资源描述规范,一定程度上阻碍了其信息的共享与交流。鉴于此,本研究通过开展芒属植物种质资源描述和数据制定技术标准研究,旨在为芒属能源作物品种的选育、审定与推广提供科学规范的依据。本文论述了芒属种质资源描述规范、数据标准与数据质量控制规范的制定原则、方法与内容,对于促进整合全国芒属种质资源,规范芒属种质资源的收集、保存、评价具有指导作用。     

甘薯种质超低温保存研究进展

甘薯是重要的粮食及经济作物,其种质保存一般采用田间种质圃和离体试管苗保存两种方式.但因甘薯的生理特性及这两种保存方式本身存在的弊端,有必要开展新的保存方法研究.超低温保存是目前甘薯种质长期安全保存的最有效方式.本文对甘薯超低温保存的定义、方法及存在的问题和展望进行了论述,并对茎尖玻璃化法进行了详细介绍.     

首部作物种质资源安全保存专著《作物种质资源安全保存原理与技术》正式出版

作物种质资源的安全保存是其有效利用的前提,安全保存需要确保维持种质高生活力和遗传完整性。国家农作物种质资源种质库圃已经收集保存超过51万份作物种质资源,此外各省、研究机构、育种单位也保存有大量作物种质资源。然而入库圃保存并不是一劳永逸的,种质库保存的资源会面临因活力下降而丧失的风险,种质圃保存的资源易遭受自然灾害和生境恶化等威胁,也存在丧失的风险。     

悬钩子属田间基因库的建立与维护

江苏省植物研究所、中国科学院植物研究所在进行了7个省悬钩子属（RubusL.）种质资源调查的基础上,1993年获得国家自然科学基金资助,在南京建立了我国第一个悬钩子属田间基因库,开展了是钩子属种质资源评价的研究。本文论述了悬钩子植物在植株大小、地上部寿命和直立性、前蘖发生、顶端生根特性以及生态适应性等方面的遗传多样性及与此相应的田间基因库建设和维护措施。     

云南省作物种质资源的研究现状及利用前景

云南是中国作物种质资源最为丰富的省份之一,已收集保存各类作物种质资源2万余份,并在水稻、小麦、玉米、甘蔗、茶叶、油料、花卉等资源的利用方面开展了一系列的研究,取得了丰硕的成果。本文将在分析云南作物种质资源利用研究的基础上,论述云南作物种质资源在育种、科研、国际交流等方面的利用途径与发展前景。     

云南省作物种质资源的研究现状及利用前景

云南是中国作物种质资源最为丰富的省份之一,已收集保存各类作物种质资源2万余份,并在水稻、小麦、玉米、甘蔗、茶叶、油料、花卉等资源的利用方面开展了一系列的研究,取得了丰硕的成果。本将在分析云南作物种质资源利用研究的基础上,论述云南作物种质资源在育种、科研、国际交流等方面的利用途径与发展前景。     

作物野生近缘种的保护与利用

作物野生近缘种将是保证下一世纪粮食充足的重要因素。近30余年来国际国内非常重视作物野生种质资源的搜集、保存、鉴定、评价和利用的研究。我国作物野生近缘种特别丰富,同时受威胁非常严重。因此,加大力度开展作物及其野生近缘种种质资源的遗传多样性、保存技术、种质创新和利用的研究是刻不容缓的。     

桃花粉低温和超低温保存方法比较研究

桃(Prunus persica(L.)Batsch)是我国重要的无性繁殖作物种质资源,目前主要保存于3个国家无性繁殖作物种质圃。随着以茎尖、花粉、休眠芽为保存载体的超低温保存技术的发展,超低温保存已成为无性繁殖作物重要备份保存方式。本研究以15份桃种质花粉为研究对象,开展含水量、回湿处理和保存温度(4℃低温保存和液氮超低温保存)对保存后花粉离体萌发率的影响研究。研究结果:明确了桃种质花粉超低温保存的含水量;揭示了回湿处理对部分桃种质花粉超低温保存产生显著影响;超低温保存后花粉离体萌发率最高可达83%;4℃低温保存和超低温保存比较研究结果表明,超低温保存4年后14份桃种质花粉离体萌发率仍可保持30%以上,11份桃种质花粉离体萌发率与保存前花粉离体萌发率相比无显著变化甚至显著提高,而4℃低温保存的花粉离体萌发率降至0。该研究为国家种质库建立花粉规模化超低温保存提供技术支撑。     

苎麻种质资源保存技术研究进展

苎麻是重要的经济作物,本文简要阐述了苎麻种质资源的分布状况,介绍了中国苎麻种质资源的保存现状,总结了苎麻种质资源田间栽培保存技术及室内保存技术的研究进展。并且针对目前单一的保存方法进行了讨论和分析,提出了自己的看法和建议。     

Characterization and development of EST-SSR markers to study the genetic diversity and populations analysis of Jerusalem artichoke (<Emphasis Type="Italic">Helianthus tuberosus</Emphasis> L.)

In recent years, Jerusalem artichoke has received widespread attention as a novel source of sugar, biofuel, and animal feed. Currently, only few gDNA-SSRs derived from sunflower were verified in the Jerusalem artichoke; therefore, it is particularly important to develop SSR primer markers that belonged to Jerusalem artichoke resources. Using EST data to develop EST-SSR markers is simple and effective. In order to understand the general characteristics of SSR markers in Jerusalem artichoke EST sequences and accelerate the use of SSR markers in Jerusalem artichoke research. This study used 40,370 sequenced unigene fragments and MISA software to identify SSR loci. The 48 pairs of EST-SSR primers assessed for the identification of 45 varieties of Jerusalem artichoke. Cluster, genetic diversity parameters and AMOVA analysis was conducted using the genetic similarity coefficient, revealing genetic differences between 48 genetic material. A total of 1204 SSR loci were identified with 13 different types of repeats, distributed among 1020 EST sequences, of which trinucleotide repeats were the most common, accounting for 38.21% of the total SSR loci. Among the 44 repeat motifs, AG/CT, AAG/CTT, and ATC/ATG motifs had the highest frequencies, accounting for 22.45, 14.71, and 7.84% of all motifs, respectively. From these sequences, 48 pairs of EST-SSR primers were designed, and 22 primer pairs for loci with high polymorphism were selected to analyze the genetic diversity of 45 Jerusalem artichoke germplasm sources. The results indicated that the variation range of the effective number of alleles for 22 primers ranged between 1.7502 and 4.5660. The Shannon’s information index ranged between 0.6200 and 1.6423. The variation range of PIC ranged between 0.3121 and 0.6662 with an average of 0.5184. Cluster analysis was conducted using the genetic similarity coefficient, revealing significant genetic differences between Asian and European genetic material. Cluster analysis revealed a relationship between the genotypes and geographic origins of the Jerusalem artichoke. The results of AMOVA as well as the genetic identity and genetic distance in the Jerusalem artichoke population showed that there presented certain genetic heterogeneity in Jerusalem artichoke genetic structure of 45 samples from seven different geographic populations. The Jerusalem artichoke EST-SSR marker system established in this study provides an effective molecular marker system for future research focused on Jerusalem artichoke genetic diversity and the breeding of new varieties.     

Genetic diversity of worldwide Jerusalem artichoke (Helianthus tuberosus) germplasm as revealed by RAPD markers

Jerusalem artichoke (Helianthus tuberosus) is a wild relative of the cultivated sunflower (H. annuus); it is an old tuber crop that has recently received renewed interest. We used RAPD markers to characterize 147 Jerusalem artichoke accessions from nine countries. Thirty RAPD primers were screened; 13 of them detected 357 reproducible RAPD bands, of which 337 were polymorphic. Various diversity analyses revealed several different patterns of RAPD variation. More than 93% of the RAPD variation was found within accessions of a country. Weak genetic differentiation was observed between wild and cultivated accessions. Six groups were detected in this germplasm set. Four ancestral groups were found for the Canadian germplasm. The most genetically distinct accessions were identified. These findings provide useful diversity information for understanding the Jerusalem artichoke gene pool, for conserving Jerusalem artichoke germplasm, and for choosing germplasm for genetic improvement.     

Heterologous expression of <Emphasis Type="Italic">PDH47</Emphasis> confers drought tolerance in <Emphasis Type="Italic">indica</Emphasis> rice

Jerusalem artichoke (Helianthus tuberosus L.) cultivars are conserved in genebanks for use in breeding and horticultural research programs. Jerusalem artichoke collections are particularly vulnerable to environmental and biological threats because they are often maintained in the field. These field collections could be securely conserved in genebanks if improved cryopreservation methods were available. This work used four Jersualem artichoke cultivars (‘Shudi’, ‘M6’, ‘Stampede’, and ‘Relikt’) to improve upon an existing procedure. Four steps were optimized and the resulting procedure is as follows: preculture excised shoot tips (2–3 mm) in liquid MS medium supplemented with 0.4 M sucrose for 3 days, osmoprotect shoot tips in loading solution for 30 min, dehydrate with plant vitrification solution 2 for 15 min before rapid cooling in liquid nitrogen, store in liquid nitrogen, rapidly rewarm in MS liquid medium containing 1.2 M sucrose, and recover on MS medium supplemented with 0.1 mg L^?1 GA₃ for 3–5 days in the dark and then on the same medium for 4–6 weeks in the light (14 h light/10 h dark). After cryopreservation, Jerusalem artichoke cultivar ‘Shudi’ had the highest survival (93%) and regrowth (83%) percentages. Cultivars ‘M6’, ‘Stampede’, and ‘Relikt’ achieved survival and regrowth percentages ranging from 44 to 72%, and 37–53%, respectively. No genetic changes, as assessed by using simple sequence repeat markers, were detected in plants regenerated after LN exposure in Jerusalem artichoke cultivar ‘Shudi’. Differential scanning calorimetry analyses were used to investigate the thermal activities of the tissues during the cryopreservation process and it was determined that loading with 2.0 M sucrose and 0.4 M sucrose dehydrated the shoot tips prior to treatment with PVS2. Histological observations revealed that the optimized droplet vitrification protocol caused minimal cellular damage within the meristem cells of the shoot tips.     

菊芋在脱脂乳中对双歧杆菌生长的影响研究

以菊芋粉为材料,以长双歧杆菌(Blm)和两歧双歧杆菌(Bbm)为实验菌株,研究菊芋在脱脂乳中对双歧杆菌生长的影响,以期为进一步开发菊芋资源和研制双歧杆菌酸奶提供理论依据。结果表明在脱脂乳中加入3%的菊芋粉,凝乳时间有所缩短,在接种Blm的脱脂乳中缩短了0．9h,在接种Bbm的脱脂乳中缩短了1．1h。在脱脂乳中添加3%的菊芋粉后,明显促进了菌体产酸。     

DNA methylation of Quercus robur L. plumules following cryo-pretreatment and cryopreservation

Pedunculate oak (Quercus robur) is an ecologically and economically important forest tree species which produces seeds that are classified as recalcitrant. Thus, cryopreservation of seed meristems is a method for long-term preservation of this germplasm in gene banks. During cryopreservation, many factors, such as desiccation, cryoprotection and cooling/rewarming, can induce stress in the frozen meristems. In this study, in vitro survival and the global DNA methylation level of plumules after cryoprotection, desiccation and cryostorage was evaluated. Results indicated that both desiccation and storage in liquid nitrogen have negligible influence on DNA methylation status of Q. robur plumules. These findings support the cryopreservation of plumules as an appropriate method for conservation of Q. robur germplasm.     

植物种质超低温保存遗传稳定性的研究进展

超低温保存被认为是种质长期保存最有效的方法,其中生物材料低温保存的遗传稳定性是植物种质资源保存中最受关注的问题之一。本文对近年来超低温保存后植物材料的遗传稳定性及变异的研究情况进行了介绍,涉及表型性状分析、基因组遗传稳定性、表观遗传变化及超低温保存的筛选效应等,为进一步研究超低温保存的应用提供参考。