Study on Rational Breeding of High-Yield Avermectin Industrial Strain

[Objective] Strain Biok Av-023 used as the control was employed on screening of high-avermectin yield mutants by rational screening.[Method] With Biok Av-023 as the original strain,the positive mutation strain was firstly screened by routine UV mutagenesis,and then the high-yield avermectin producing strain was selected by the breeding way inferred by L-Ile induction.[Result] UV mutation and L-Ile directional screening had showed that the best L-Ile screening concentration was 0.5%,and the high-yield mutation strain AV60s-32 after re-screening reached the highest titer of 4520 IU/ml,which increased by 23.4% compared with the original strain.[Conclusion] The production of avermectin can be effectively enhanced by the combined way of UV mutation and L-Ile rational breeding.

Study on Seedling Techniques of Artocarpus nanchuanensis

[Objective] This study aimed to solve the problems of low seed germina- tion rate and difficult bareroot seedling transplanting in artificial cultivation of Arto- carpus nanchuanensis, a native species in China. [Method] Under different seed treatment and seedling style, the seed germination rate and seedling emergence rate of A. nanchuanensis were investigated. [Result] tn both sand bed and direct sowing yellow soil, the seed germination rate, seedling survival rate and seedling emergence rate in the treatment II were all higher than those in the treatments I and III. The average seed germination rate, seedling survival rate and seedling emergence rate in sand beds were 1.5%, 16.27% and 13.95%, respectively higher than those in direct sowing yellow soil. The average seedling emergence rate in sand beds was 2.46% higher than that in containers. Among the 8 kinds of light matrix formulas, the growth of seedlings in the formula VIII was best. In the three treatment groups, the seedling emergence rates, seedling heights and ground diame- ters in the formula VIII were all significantly different from those in the other formu- las. The seedling growth in the formula I and III ranked second, while the seedling emergence rate, seedling height and ground diameter in the formula VII were the poorest. [Conclusion] If conditions allow, the formulas I （meadow soil：vermiculite：yel- low soi1=5：3：2）, III （meadow soil：perlite：yellow soi1=5：3：2） and VIII （peat：forest top soi1=6：4） should be promoted in seedling with light matrixes.

A Preliminary Study on Breeding of Ideal Plant in Millet

To further increase millet yield, the ideal plant in millet has become the goal of high yield breeding for millet. Taking crossbreeding or dynamic breeding technique as dominant and technologies such as modern selection or system selection as subsidiary, progenies with ideal plant are selected by using new germplasms such as Lilvgu and Lizigu with the significant difference in plant type to other cultivars as parents. The ge- netic characteristics of new germplasms in breeding are also emphatically analyzed to summarize the breeding experience of ideal plant, which has been proved that the combination of ideal plant and heterosis utilization is one of the important ways to raise millet yield breakthrough.

Red fluorescent protein (DsRed2), an ideal reporter for cotton genetic transformation and molecular breeding

Genes encoding reporter proteins are used as visual marker-assisted tools in genetic transformation as well as plant breeding. In this study, the red fluorescent protein identified in Discosoma sp. coral(DsRed2) was successfully used as a visual marker for cotton genetic engineering. DsRed2 was successfully expressed in two cotton cultivars,JIN668 and YZ1, driven by the Ca MV-35 S promoter via the Agrobacterium-mediated transformation. Our results suggest that DsRed2 expression provides an early-stage selection tool for the transgenic calli via visual observation. Red fluorescence can be detected not only in callus and somatic embryos but also in most tissues and organs of mature plants. The transgenic line Yz-2-DsRed2 was crossed with four different cotton cultivars to assess the transgene heritability and stability in different genetic backgrounds.The heritability of the red color was highly stable when Yz-2-DsRed2 was used as a male parent. The DsRed2 gene expressed 100% in the F_1 hybrids. To investigate the relationship between DsRed2 transcription and DNA methylation, a methylation-specific PCR approach was applied to the Ca MV-35 S promoter region. The results showed a negative association between DNA methylation level in the promoter region and the transgene transcription.Taken together, these findings suggest DsRed2 a visual reporter gene for cotton genetic transformation and molecular breeding programs.

Recent Research Progress in Foxtail Millet(Setaria italica)

Foxtail millet （Setaria italica L. Beauv.）, as a significant food and fodder cereal crop, was widely cultivated in the Yellow River Valley and is still a kind of farming tradition of millet in Northern China. With the development of agriculture and the improvement of people＇s living standards, foxtail millet＇s planting area has be- come less and less in arid and semi-arid region now. However, because of its small diploid genome （1C genome size=420 Mb） and self-pollination, foxtail millet is very suitable for whole genome sequence and is used as an experimental model plant for C4 photosynthesis and biofuel research. In 2012, the completed genome sequence of foxtail millet had been successfully produced by the Beijing Genomics Institute （BGI） and US Department of Energy Joint Genomic Institute （JGI）, respec- tively. It will be used as an experimental crop to explore many aspects of plant ar- chitecture, physiology and biochemistry, comparative and functional genomics studies in the bioenergy grasses. To systematically understand the recent research progress in foxtail millet; we summarize the following aspects in this study： germplasm, tradi- tional breeding, physiology and biochemistry, molecular marker, construction of genet- ic linkage map, gene localization, genome sequencing and comparative genome. This may be a door to open for the further development of foxtail millet in the future.

Breeding, Nursing and Biology of Thai Mahseer （Tor tamboides） in Malaysia： An Overview

The Thai mahseer is one of the high-value freshwater fish species, especially m Malaysia where it is cultured commercially but poorly known in Thailand. This paper reviews a recent knowledge necessary for commercial culture of Thai mahseer based on the breeding and rearing practices in Malaysia. Breeding data shows that this species can be spawned all year round. On average, the size of mature female that can be induced to spawn is 678 mm total length （TL） and 3,817 g in weight and the size of mature male is 599 mm TL and 2,414 g in weight. Induced spawning using an analogue of sGnRH Ovaprim at 0.5 ml/kg body weight （BW） is the most successful hormone treatment and dosage for Thai mahseer. The average number of eggs is 875 egg/kg BW. Eggs of the Thai mahseer are spherical, demersal and non-sticky, and hatching occurs 69-90 hours post-fertilization. At 60 weeks of age, average body weight is 179 g. Polynomial regression analysis revealed a maximum specific growth rate at 48% dietary protein. General biology, water quality requirements, feeding strategies and genetic structure of the Thai mahseer are also summarized in this paper.

Developmental ecology of the American horseshoe crab Limulus polyphemus

During spawning events, horseshoe crab eggs are released from the female＇s oviducts, and fertilized by one or more males. Eggs are shaped by the female into discrete clutches deposited in nests at depths of 10-20 cm on intertidal estuarine beaches. Distinguishing between fxesh eggs and the early developmental stages is obfuscated by the large amount of dense, opaque yolk. The first unambiguous confirmation of development is the formation of the rudimentary prosomatie appendages at the ＂limb bud＂ stage. Several days thereafter, the outer chorion is shed and the developing embryo expands and undergoes a series of molts within the clear inner egg membrane. The trilobite （first iustar） stage thus attained may remain within the beach sedi- ments for several more weeks, until hatching is facilitated by environmental factors such as hydration, agitation, and osmotic shock that accompany the infiltration of seawater into the nests. Trilobites exhibit endogenous eirgatidal swimming rhythms that are entrained by mechanical agitation, suggesting that peaks in larval swimming are timed to coincide with periods of high water and the inundation of the nests. Larval swimming is limited and does not appear to result in long-distance dispersal. The limited dispersal of the larvae has important implications for the population dynamics of relatively isolated populations. The rate of larval development is highly plastic and is influenced by temperature, salinity, dissolved oxygen, and the presence of pollutants. The broad environmental tolerances of horseshoe crab embryos and larvae are important in understanding their current geographic distribution and their evolutionary persistence

History of Apartheid Education and the Problems of Reconstruction in South Africa

This paper outlines the rationale of Bantu education that was available for South African Blacks from 1953 to 1992. The paper is of the opinion that challenges of constructing a new education system in post-apartheid South Africa cannot be fully grasped without a proper understanding of the pervasive impact of Bantu education on the majority for a period of almost 60 years. It also discusses the educational vision and goals of the important organizations in the liberation movement such as the African National Congress, the Azanian People＇s Organization, and the Pan Africanist Congress that continue to shape educational debates in the present educational reform context. The paper argues that the present curriculum by its very history and origins does not address the problems that have been created by the ideology of the former South African education system. Salient to these problems is the over-emphasis on Christian/European education that is not realistic in many regions of South Africa. The paper argues that curriculum has to reflect the cultural and racial diversity in South Africa, and further suggests that all languages and cultures in South Africa are essential in the building of an anti-racist and anti-sexist society. The monitoring of academic activity in a democratic education system can be confusing to teachers who have been trained within the confines of an apartheid （Bantu） education. The paper therefore suggests that more funds will have to be put aside by the government to upgrade the pedagogical approach of teachers so that they can be able to deal with their new role of leadership and the developing of content, and tackle issues of sexism/racism both in and out of the classroom.

分子植物育种 作者投稿指南

1刊登范围本刊是一份为转基因育种、分子标记辅助育种及常规育种服务的国际化科学杂志。围绕水稻、小麦、玉米、油菜、大豆、棉麻、薯类、果树、蔬菜、花卉、茶叶、林木和草业等,刊登分子遗传育种理论、分子育种方法、分子育种研究动态以及优良种质培育等方面的科学论文应用成果。2栏目设置本刊设置固定栏目和随机栏目。固定栏目常设研究论文(Research Article)和研究报告(Research Report),主要发表最新的原始研究成果。随机栏目根据稿源可能设研究评述(A Review)。

分子植物育种作者投稿指南

1刊登范围本刊是一份为转基因育种、分子标记辅助育种及常规育种服务的国际化科学杂志。围绕水稻、小麦、玉米、油菜、大豆、棉麻、薯类、果树、蔬菜、花卉、茶叶、林木和草业等,刊登分子遗传育种理论、分子育种方法、分子育种研究动态以及优良种质培育等方面的科学论文应用成果。2栏目设置本刊设置固定栏目和随机栏目。固定栏目常设研究论文(Research Article)和研究报告(Research Report),主要发表最新的原始研究成果。