Subjects: Biology >> Botany >> Applied botany submitted time 2023-12-24 Cooperative journals: 《广西植物》
Abstract： Camellia sinensis var. sinensis cv. ‘Liupao’ is the main raw material for making Liupao tea. To explore the genetic background of C. sinensis var. sinensis cv. ‘Liupao’, especially its phylogenetic position and evolutionary history, 27 and five individuals of C. sinensis var. sinensis cv. ‘Liupao’ and C. costata were sampled for genome skimming and transcriptomic sequencing. The phylogenetic relationship between C. sinensis var. sinensis cv. ‘Liupao’ and other Camellia was reconstructed, the divergence time of the chloroplast genome sequences of C. sinensis var. sinensis cv. ‘Liupao’ was estimated, and the genetic diversity was investigated. The results were as follows: (1) On the chloroplast tree, 27 samples of C. sinensis var. sinensis cv. ‘Liupao’ were divided into two distantly-related groups, one was nested within a clade mainly consisting of C. sinensis, being interspersed among other cultivated C. sinensis, while the other group formed as a well supported lineage that was most closely-related to and nested within C. costata; On the nuclear gene tree, however, all the 27 samples formed a clade with other C. sinensis as well as some other Camellia species with generally unresolved relationships among them. Despite the lack of resolution in this clade, it was definitely far separated from C. costata; The cytonuclear phylogenetic conflict suggested once ancient introgression hybridization of C. costata with the ancestor of some C. sinensis var. sinensis cv. ‘Liupao’ individuals so that the latter captured the chloroplast genome of the former. (2) The time estimate indicated that the introgression hybridization event occurred in the Quaternary period, ca. 1.55 million years ago, long before the history of tea cultivation and production by humans. (3) In addition, both the chloroplast genomes and nuclear genes revealed that the C. sinensis var. sinensis cv. ‘Liupao’ had high haplotype diversity, possessing high evolutionary potential. This study could provide important references for the germplasm protection, breeding, and utilization of high-quality C. sinensis var. sinensis cv. ‘Liupao’ strains.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-08-05 Cooperative journals: 《广西植物》
Abstract： Chromosome numbers and genome ploidy are crucial basic information for evolutionary biology and genetics. Hemiboea, a genus of Gesneriaceae, with about 44 species, is mainly distributed in southern China, which have important medicinal and ornamental value. It is difficult to obtain suitable root tips for the chromosome preparation because of their small twining roots and small chromosomes. So far, only the chromosome numbers from three species of Hemiboea have been reported, while the chromosome numbers and ploidy of most species are unknown. The relationship between the pattern of chromosome number evolution and species evolution is also unclear. In this study, in order to explore the optimal conditions for chromosome preparation and the relationship between chromosome numbers and species evolution of Hemiboea, firstly, the root tips of six species (including H. subcapitata, H. longgangensis, H. longzhouensis, H. subacaulis var. jiangxiensis, H. follicularis, and H. yongfuensis), which were generated by the method of hydroponic rooting for cutting leaves based on the characteristics of leaf cuttage propagation of plants in the Hemboea, were used for the chromosome experiments. Then, we assessed the effects of different experimental conditions on chromosome preparation, and then, the conditions were optimized and the chromosome counting was performed. Finally, the evolutionary history of chromosome numbers in Hemiboea and the related genera including Anna and Loxostigma were traced based on the molecular phylogenetic relationships, and the evolutionary pattern of chromosome numbers and relationships with species evolution were studied. The results were as follows :(1) The optimal condition for karyotype preparation of the plants in Hemiboea are sampling during 9:30-10:00 am, dissociating for 10 min, and staining for 15 min. (2) All the six species of Hemiboea are diploid and with 32 chromosome numbers (2n=2x=32). (3) Except for a few species in the genus, the chromosome numbers of most species may be 2n=2x=32, and the variation of chromosome numbers may be caused by aneuploidy, which has no obvious relationship with the species evolution. This study shed light on chromosome preparation of Hemiboea and other groups with similar leaf regeneration characteristics, and provides implications for the classification and phylogeny of this group.
Subjects: Biology >> Botany >> Applied botany submitted time 2020-11-27 Cooperative journals: 《广西植物》
Abstract：大豆RLPK2 基因（GenBank 登录号: AY687391）是一个编码N-末端富含亮氨酸重复序列的类受体蛋白激酶基因。为分析大豆RLPK2 基因的功能，通过农杆菌介导法转化野生型拟南芥，构建了大豆RLPK2 基因过表达载体。该研究以野生型拟南芥和大豆RLPK2 基因过表达拟南芥植株为材料，分析了叶片衰老过程中叶绿素荧光参数、抗氧化酶活性及衰老相关基因表达量的变化。结果表明：（1）无论是野生型还是转基因拟南芥，随着叶片衰老进程的进行，光系统II（PSII）的最大光化学效率（Fv/Fm）、PSII 实际光化学效率（ΦPSII）、光化学淬灭系数（qP）和光合电子传递速率（ETR）均呈下降趋势，但后者下降趋势更明显；（2） 激发压（1-qP）在叶片衰老前期的变化较为平稳，后期则急剧增加，且转基因型比野生型拟南芥增加更明显；（3）在叶片衰老的各个时期，转基因拟南芥叶片丙二醛（MDA）含量均显著高于野生型，而超氧化物岐化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性均显著低于野生型；（4）实时荧光定量PCR 检测结果表明，RLPK2 转基因拟南芥中衰老标志基因ATSAG12，衰老关键转录因子ATNAP、ATWRKY6 和叶绿素降解关键酶编码基因ATACD1 等表达量显著上调。综上所述，大豆类受体蛋白激酶基因RLPK2 参与调控植物叶片衰老进程，其表达对叶片衰老起促进作用。
Subjects: Biology >> Botany >> Applied botany submitted time 2020-08-02 Cooperative journals: 《广西植物》
Abstract：半蒴苣苔（Hemiboea subcapitata）为苦苣苔科半蒴苣苔属多年生草本植物。该种形态变异幅度大，曾包括多个变种；分布范围广，在多种类型的生境基质上皆有分布。本研究包括典型半蒴苣苔和与之近缘，且曾被归为其变种的翅茎半蒴苣苔(H. pterocaulis)，以及我们新发现的与两者形态上分别最相近的另两种变异类型，对其关键形态、微形态的多样性进行了描述和比较；结合查阅标本、文献资料以及长期的野外追踪调查，统计分析了半蒴苣苔不同类型间的地理和生境分布；此外，通过DNA证据，初步重建各物种及变异类型间的系统发育和单倍型进化关系。研究结果表明：(1)通过茎、叶、花和开花物候等多性状组合能够区分半蒴苣苔复合群各类型。(2)半蒴苣苔复合群四类型间在叶表皮细胞形状和气孔分布等方面无甚区别；而在表皮毛的有无、复表皮层数、维管束数量和排布存上存在差别，或有助于分类。(3)典型半蒴苣苔广泛分布于我国中部至南部，向南延伸至越南北部，在石灰岩、丹霞等生境基质上皆有分布；翅茎半蒴苣苔仅分布于广西桂林市小部分区域的喀斯特山石灰岩基质上；而另两种变异类型则分布更为狭域，仅分布于桂林市永福县一个或相邻的数个喀斯特山石灰岩基质上。(4)DNA单倍型网络图分析表明，半蒴苣苔复合群四类型各自独享单倍型；但重建分子系统发育关系则表明，金钟山居群与翅茎半蒴苣苔聚为一支，两者亲缘关系最近但相互之间不成单系，金钟山居群是否为独立物种还需更多证据加以检验，而半蒴苣苔则与永福半蒴苣苔两者间互为单系，支持两者为独立物种。
Hits
Hits
Downloads
Comment