十字花科植物黄化突变特性及其分子机制研究进展

十字花科Brassicaceae植物多数生长发育时间短,生长过程中自然发生,或使用物理或化学方法诱导,常会出现一些颜色较淡或金黄的突变个体即黄化突变体。这些突变体表型直观,表现为植株矮小,叶绿素较低,植株光合作用受抑制,产量降低,因此黄化突变常被视为有害突变。但近20 a来黄化突变体日益受到研究者们的重视与青睐,被用于研究植物叶绿体结构、叶绿素合成代谢等方面。本研究简要介绍了十字花科植物常见的黄化突变类型及其主要的外观特征,综述了十字花科植物黄化突变体的叶绿体超微结构、光合色素及其光合性能,并对十字花科植物黄化突变的遗传特性、分子机制进行了讨论,为十字花科植物叶色突变研究及新品种选育提供理论基础。参52     

十字花科植物蜡质形成特性及分子机制研究进展

十字花科Brassicaceae包含蔬菜、油料作物、药用植物、观赏植物和染料植物等,是一类1年生、2年生或多年生的植物,是中国最重要的蔬菜和油料作物之一。蜡质的主要成分是超长链脂肪酸及其衍生物,十字花科植物的蜡质是其适应外界环境变化而形成的保护结构,在维持水分平衡、反射紫外线、减少外来机械损伤、降低低温伤害、抵御细菌真菌入侵、防止果实开裂与昆虫侵食等抵抗生物与非生物胁迫中起着重要作用。对十字花科植物蜡质类型、生理功能、遗传特性、合成与转运途径等方面进行综述,可为十字花科植物的蜡质代谢研究提供参考。图2表2参61     

流式细胞术在测定竹类植物基因组大小中的应用

  目的  分析竹类植物不同组织部位及不同处理方法对其基因组大小的影响,可提高植物基因组大小测定精度。  方法  以竹类植物叶片和笋为材料,以水稻Oryza sativa为参照,设置细胞核染色时间为1、3、5、7、9、12、18、24和30 min共9个梯度,利用流式细胞仪对不同组织部位及处理的基因组大小进行分析。  结果  ①对同一竹种而言,其叶片和笋流式峰形图相似,基因组大小仅存在微小差异,差值为0.04~0.20 pg。②不同竹种对染色时间要求不同,其中,唐竹Sinobambusa tootsik、花叶唐竹Sinobambusa tootisik f. albo-striata、平安竹Pseudosasa japonica var. tsutsumiana、曙筋矢竹Pseudosasa japonica f. akebono、美丽箬竹Indocalamus decorus、花叶赤竹Sasaella glabra f. albo-striata及红秆寒竹Chimonobambusa mamorea f. variegata染色1 min即达到最大荧光峰值,孝顺竹Bambusa multiplex和黄皮绿筋竹Phyllostachys sulphurea染色3 min达到最大峰值,茶竿竹Pseudosasa amabilis var. amabilis和柳叶细竹Thyrsostachy ssiamensis染色5 min达到最大峰值,仅黄皮刚竹Phyllostachys sulphurea(叶片)7 min达到最大峰值。③12个竹种的荧光强度在1~30 min内存在较大变化,除茶竿竹、柳叶细竹、孝顺竹叶片及唐竹笋外,其他竹种的荧光强度变化值均在5%以上,特别是平安竹和花叶赤竹变化更大,分别为12.93%和12.88%。④热带木本竹种孝顺竹和柳叶细竹基因组大小为(1.64±0.54)~(2.69±1.01) pg,其他10个温带竹种基因组大小为(3.76±1.51)~(5.73±1.85) pg。10个温带竹种中,刚竹属Phyllostachys竹种基因组较小,大小为(3.76±1.51)~(3.91±0.95) pg,其他竹属的一些竹种基因组较大,大小为(4.82±0.54)~(5.73±1.85) pg。  结论  ①竹类植物叶片和笋均可作为基因组大小分析材料,细胞核染色时间对基因组大小测定结果存在一定影响,染色时间以3~5 min最佳。②热带木本竹种基因组大小明显小于温带木本竹种,温带木本竹种中,刚竹属竹种的基因组大小明显小于其他竹种。图1表5参29     

Two novel gene-specific markers at the Pik locus facilitate the application of rice blast resistant alleles in breeding

Blast, a disease caused by Magnaporthe oryzae, is a major constraint for rice production worldwide. Introgression of durable blast resistance genes into high-yielding rice cultivars has been considered a priority to control the disease. The blast resistance Pik locus, located on chromosome 11, contains at least six important resistance genes, but these genes have not been widely employed in resistance breeding since existing markers hardly satisfy current breeding needs due to their limited scope of application. In this study, two PCR-based markers, Pikp-Del and Pi1-In, were developed to target the specific In Del(insertion/deletion) of the Pik-p and Pi-1 genes, respectively. The two markers precisely distinguished Pik-p, Pi-1, and the K-type alleles at the Pik locus, which is a necessary element for functional genes from rice varieties. Results also revealed that only several old varieties contain the two genes, of which nearly half carry the K-type alleles. Therefore, these identified varieties can serve as new gene sources for developing blast resistant rice. The two newly developed markers will be highly useful for the use of Pik-p, Pi-1 and other resistance genes at the Pik locus in markerassisted selection(MAS) breeding programs.     

利用分子标记辅助选择培育水稻广亲和保持系

[目的]利用分子标记辅助选择培育水稻广亲和保持系,为水稻籼粳亚种杂种优势利用提供参考.[方法]用4个不育系博A、天A、青A、62A与24个水稻姊妹系杂交,测定其恢保性;同时利用与Sn5紧密连锁的SSR标记GXR6对24个姊妹系进行检测;再通过籼粳测交验证其亲和性.[结果]24个姊妹系中除B11、B13、B14、B15外,其余B1～B10、B12、B 16～B24等20个姊妹系花粉不育度均达100.0％,对4个不育系博A、青A、天A、62A均保持不育.SSR分子标记检测结果显示,B1、B2、B4～B7、B10～B12、B14～B16、B 18～B20、B22、B23等17个姊妹系均携带187R的广亲和基因Sn5;但与日本晴和巴利拉测交验证结果显示,仅B1、B4具有亲和性,B9虽未携带Sn5却具有亲和性,其测交组合F1代植株结实率极显著高于桂B测交的结实率(P＜0.01)而低于测验种自身的结实率(桂B结实率79.79％,日本晴76.87％,巴利拉73.65％),B1、B4和B9属于中亲和力品系.[结论]筛选获得的广亲和保持系B1、B4和B9,可用来改造现有不育系,充分发挥籼粳亚种杂种优势,提高杂交水稻产量,具有较好的应用前景.     

Chemical and spectroscopic characteristics of humic acid from a clay loam soil in Ontario after 52 years of consistent fertilization and crop rotation

Long-term fertilization and crop rotation can influence both organic C sequestration as well as the C composition of soils and the more resistant organic C compounds contained in humic acid(HA). This study examined the effects of fertilization and cropping type(monoculture corn(MC) and Kentucky bluegrass sod(KBS) and corn-oat-alfalfa-alfalfa rotation(RC)) on the HA composition of soil from a 52-year field study in southern Ontario, Canada. Humic acid samples were extracted from soil, and elemental analysis, infrared spectroscopy, solid state 13C nuclear magnetic resonance spectra, and electron paramagnetic resonance methods were used to determine the influence of the cropping type on the characteristics of HA. Both fertilization and cropping type affected the chemical characteristics of HA. Fertilization led to a 5.9% increase in C, a 7.6% decrease in O, and lower O/C and(N + O)/C ratios in HA as compared to the corresponding non-fertilized treatments. Rotation resulted in a lower proportion of C(48.1%) and a greater(N + O)/C ratio(0.7) relative to monoculture cropping. Infrared spectroscopy analysis showed that HA contained more C-O groups in fertilized soil than in non-fertilized soil under MC and KBS. Fertilization increased the O-alkyl-C, phenolic-C, and free radical contents of HA relative to non-fertilization treatments. Rotation decreased the aliphatic and carboxyl groups and increased the O-alkyl, carbohydrate, aryl, and phenolic groups and free radicals, relative to MC and KBS. Both long-term crop rotation and fertilization dramatically modified the soil HA composition. Significant relationships were observed between the molecular composition of HA and soil organic C. Hence, humic acid characterization could be used as an indicator of the long-term sustainability of crop management practices.     

检疫性实蝇快速鉴定方法研究进展

为适应口岸检疫的需要,检疫性实蝇的快速鉴定方法不断发展。本文全面综述了检疫性实蝇电泳、限制性片段长度多态性、随机扩增多态性DNA和核酸序列分析等鉴定方法的进展,并对各种鉴定方法进行了对比,强调了准确选择分子标记的重要性,旨在为建立有效的检疫性实蝇快速鉴定方法提供基本思路。     

竹材木质素选择性降解菌株的分子鉴定

鉴定1株从腐竹中筛选的高效选择性降解竹材木质素的优良菌株ZNLD-18,为生物法提取可纺性竹原纤维奠定基础。利用真菌通用引物ITS1和ITS4扩增并测定菌株的rDNA ITS区序列,序列总长541bp。把所得序列在GenBank中进行B1ast搜索得到同源性较高的同属不同种菌株序列。比较这些序列的遗传距离,显示菌株ZNL D～18与Trametes versicolor的ITS区序列同源性为99％以上。利用PAUP软件构建分子系统发育树,通过对该树的分析并综合菌株的形态特征,鉴定菌株ZNLD-18为白腐菌Trametes versicolor。     

Molecular-Cytological Identification and Chromosome Behavior Analysis of Telotetrasomic in Rice

From the progenies of a telotrisomic of chromosome 9 short arm of an indica rice variety, Zhongxian 3037, a phenotypical variant was selected. The variant plant had rolled leaves, dispersed plant type, as well as a low seed-setting rate. Cytological and molecular cytological investigations revealed two extra chromosomes, which were the shortest in somatic cells of the variant. Fluorescent in situ hybridization (FISH) analysis using a rice centromere specific DNA (RCS2) and a DNA sequence specific for chromosome 9 on premetaphase and pachytene chromosomes showed that these two chromosomes were the short arms of chromosome 9. That is to say, the variant was a telotetrasomic of chromosome 9. Among the 25 pachytene cells, the two telosomic chromosomes paired each other to form a bivalent and didn't pair with other normal chromosome 9 as multivalents in 96% cells. However, the bivalent was easy to disassociate in advance.     

InDel and SNP Markers and Their Applications in Map-based Cloning of Rice Genes

High-density markers are necessary for map-based cloning of dca genes, but the currently available markers are not satisfactory enough. InDel (insertion-deletion length polymorphism) and SNP (single nucleotide polymorphism) are the new generation of molecular markers and can basically meet the need of fine mapping. InDel and SNP markers can be developed through bioinformatics. These markers are valuable markers with the characters of low cost, high specificity and stability. This article introduced the methods for designing InDel and SNP markers, taking the mapping of a dce rolled leaf gene as an example. In addition, some key factors in improving the design efficiency were also discussed.