Pre-Breeding Genetic Diversity Assessment of Tomato(Solanum lycopersicum L.)Cultivars Based on Molecular,Morphological and Physicochemical Parameters

Appropriate knowledge of the parental cultivars is a pre-requisite for a successful breeding program.This study characterized fruit yield,quality attributes,and molecular variations of ten tomato cultivars during three consecutive generations under greenhouse conditions.Peto 86,Castle Rock,and Red Star cultivars showed the highest fruit yield(kg/plant),total phenolic compounds(TPC),and sap acidity.Principal component analysis categorized the evaluated fruit yield into three groups based on their quality attributes.A robust positive correlation appeared among traits inside each group.A positive correlation was likewise noticed between the first and the second groups.However,a negative correlation was detected between the first,the second and the third group.Molecular profiling,using seven inter-simple sequence repeat(ISSR)primers,produced 60 loci,including 49 polymorphic loci.The molecular analysis also pinpointed the highest genetic similarity(0.92)between P73 and Moneymaker,while the lowest genetic similarity(0.46)was observed between Castle Rock and Moneymaker.The cultivars P73 and Moneymaker showed the lowest genetic distance(2.24),while the highest genetic distance(5.92)was observed between Super Marmand and Peto86,on the one hand,and between Castle Rock and Moneymaker,on the other hand.The chemical analysis of fruit sap indicated the highest levels of TPC,total flavonoids,anthocyanin,ascorbic acid and total soluble solids in Peto 86 and Castle Rock cultivars.Phylogeny analysis of tomato cultivars based on morphological and molecular attributes indicated four distinct clades.Peto 86,Castle Rock,and Red star cultivars can be recommended for the tomato hybridization breeding programs in the future,with other tomato cultivars as potentially high-yielding parents.

Improving the phenotypic expression of rice genotypes:Rethinking “intensification” for production systems and selection practices for rice breeding

Intensification in rice crop production is generally understood as requiring increased use of material inputs: water, inorganic fertilizers, and agrochemicals. However, this is not the only kind of intensification available. More productive crop phenotypes, with traits such as more resistance to biotic and abiotic stresses and shorter crop cycles, are possible through modifications in the management of rice plants, soil, water, and nutrients, reducing rather than increasing material inputs. Greater factor productivity can be achieved through the application of new knowledge and more skill, and(initially) more labor, as seen from the System of Rice Intensification(SRI), whose practices are used in various combinations by as many as 10 million farmers on about 4 million hectares in over 50 countries. The highest yields achieved with these management methods have come from hybrids and improved rice varieties, confirming the importance of making genetic improvements. However,unimproved varieties are also responsive to these changes, which induce better growth and functioning of rice root systems and more abundance, diversity, and activity of beneficial soil organisms. Some of these organisms as symbiotic endophytes can affect and enhance the expression of rice plants' genetic potential as well as their phenotypic resilience to multiple stresses, including those of climate change. SRI experience and data suggest that decades of plant breeding have been selecting for the best crop genetic endowments under suboptimal growing conditions, with crowding of plants that impedes their photosynthesis and growth, flooding of rice paddies that causes roots to degenerate and forgoes benefits derived from aerobic soil organisms, and overuse of agrochemicals that adversely affect these organisms as well as soil and human health. This review paper reports evidence from research in India and Indonesia that changes in crop and water management can improve the expression of rice plants' genetic potential, thereby creating more productive and robustphenotypes from given rice genotypes. Data indicate that increased plant density does not necessarily enhance crop yield potential, as classical breeding methods suggest. Developing cultivars that can achieve their higher productivity under a wide range of plant densities—breeding for density-neutral cultivars using alternative selection strategies—will enable more effective exploitation of available crop growth resources. Density-neutral cultivars that achieve high productivity under ample environmental growth resources can also achieve optimal productivity under limited resources, where lower densities can avert crop failure due to overcrowding. This will become more important to the extent that climatic and other factors become more adverse to crop production. Focusing more on which management practices can evoke the most productive and robust phenotypes from given genotypes is important for rice breeding and improvement programs since it is phenotypes that feed our human populations.

Fifty Years of Botanical Gardens in China

The development, distribution and features of one hundred and forty botanical gardens (BGs) in China are reported and their functions on research, conservation, display and utilization of biodiversity are summarized in this paper. The contributions to the social and economic development in the early stage of Chinese BGs with the researches of economic plant (tobacco), medicinal plant (yam) and wild fruit tree resources are evaluated. The theoretical and applied achievements in recent years in seed science, plant conservation, economic plant introduction, acclimatization and breeding are also described. A general scope of living plant collections in Chinese BGs is presented and the outstanding ones, including Magnoliaceae, Zingiberaceae, Cycadaceae, medicinal plants, Actinidia and Rhododendron are particularly mentioned. With special reference to Chinese penjing art garden and silicified wood garden, the development of scientific popularization and tourism in BGs is reviewed.

Biodiversity in a Tomato Germplasm for Free Amino Acid and Pigment Content of Ripening Fruits

Free amino acid and pigment composition in fruits at two ripening stages from a selected tomato germplasm was stu-died. The aims were contributing to knowledge on variability of ripening metabolism and identifying more consis-tently the genetic background of the plant material under analysis. Significant differences (p < 0.05) were found among ripening stages and among genotypes within ripening stage for all amino acids and pigments except by asparagine, alanine and chlorophyll b contents. The highest relative amino acid content corresponded to glutamate, glutamine, and GABA though some genotypes had relatively high asparagine content. Glutamate, glutamine and GABA performed oppositely: the former increased along ripening while the latter two decreased in their relative content. A Principal Components (PC) analysis was applied, determining that metabolites having the greatest contribution to general variability were threonine, serine, glutamate, glutamine, glycine, isoleucine, leucine, tyrosine, phenylalanine, lycopene and beta- carotene, which showed the highest association with PC1. Alanine and chlorophylls a and b were highly associated to PC2. These two first PC explained the 62% of the total variation, and genotypes were distributed according to the ripening stage in their coordinates. Accordingly, a Hierarchical Clustering resulted in a dendrogram having a relatively high cophenetic correlation (0.70), in which two well defined groups were obtained according to ripening stage. These results verified the existence of variability in the metabolism of ripening fruit for amino acids and pigments, and allowed to identify unequivocally a set of selected tomato germplasm according to the fruit metabolic profiles in these two ripening stages.

Increasing yield potential of hybrid rice through molecular breedingIncreasing yield potential of hybrid rice through molecular breeding

Rice is the staple food for more than half of the world population. The utilization of the wild abortive cytoplasmic male sterility （CMS） in 1970s has significantly raised rice yield potential. But the world＇s annual rice production will have to increase 70 percent over the next 30 years, to keep up with the demends of the growing population.

Estimation of Genetic Parameters of Turiacu Pineapple Clones and Genetic Correlation between Traits

This study aimed to estimate genetic parameters of Turia&ccedil;u pineapple clones using mixed models;and estimate genetic correlation coefficient between traits, to provide important information to breeding programs. For this, 19 pineapple plants were visually selected and its slips were collected and planted in a single environment and nine traits were evaluated. The genetic parameters of most evaluated traits presented significant differences between the 19 clones. Some traits, such as Fusarium wilt resistance, showed high magnitudes of heritability. Clones did not differ in relation to total titratable acidity (TTA) and total soluble solids (TSS). However, these traits, which have implications to fruit quality, showed to be negatively correlated to fruit mass (-0.46 and -0.67). The results indicate that the population of Turia&ccedil;u pineapple is suitable for selection, especially for Fusarium wilt resistance. Also, Turia&ccedil;u clones can be used in breeding programs of pineapple.

2023年茶树遗传育种研究进展

文章总结概述了2023年度茶树遗传育种领域取得的主要进展,包括茶树育种基础理论的创新研究、茶树育种技术的创新探索、茶树新品种的授权与登记情况。2023年度,茶树的品质成分形成、生物及非生物胁迫响应、生长发育、叶色变异等分子调控机制,仍是育种基础理论研究的热点,获得的创新性成果为培育茶树新品种提供了明确的靶基因资源;茶树泛基因组图谱首次构建成功,进一步揭示了茶树基因组扩张的遗传基础;77个茶树品种授权获得植物新品种权,83个茶树品种通过非主要农作物品种登记,为茶产业稳健发展提供了强有力的支撑。

小麦农家种成株期条锈病抗性QTL定位及其育种效应解析

条锈病是世界范围内严重影响小麦产量的重要病害。遗传和育种利用效应不清,加之不良性状连锁累赘是限制绝大多数已发掘小麦条锈病抗性基因在育种及生产中难以广泛应用的关键。前期研究发现,小麦农家种红芒麦子对我国当前小麦生产上流行的主要条锈菌生理小种及致病类群具有稳定的成株期抗性。本研究通过构建Avocet S×红芒麦子F1及F2和F2:3家系,利用分离群体分组分析法(bulked segregation analysis, BSA)并结合小麦55K SNP芯片及外显子测序技术,在7A和7D染色体上鉴定到2个来自红芒麦子的成株期条锈病抗性主效QTL(QYr.HM-7AL和QYr.HM-7DS),分别解释了11.64%~15.25%和24.33%~40.58%的表型变异。标记连锁分析、遗传和物理图谱综合分析发现,QYr.HM-7DS与已知成株期条锈病抗性基因Yr18呈高度共线性,表明该位点抗性效应来源于Yr18;而QYr.HM-7AL是一个控制小麦成株期条锈病抗性潜在新位点,并进一步开发了可用于跟踪选择该位点的KASP(kompetitive allele-specific PCR,竞争性等位基因特异性PCR)分子标记。利用绵麦1618×红芒麦子BC_1F_2遗传改良群体对来自红芒麦子成株期条锈病抗性主效QTL遗传效应及其与产量相关性状协同改良效应进行解析。结果发现,在绵麦1618遗传背景下,Yr18和QYr.HM-7AL的转育或聚合可显著降低条锈病危害,且对小麦穗长和分蘖数呈正向效应。上述研究结果表明,在小麦产量育种中可利用农家种红芒麦子进行成株期条锈病遗传改良。

基于实践能力提升的药用植物遗传育种学实验教学改革

药用植物遗传育种学是中草药栽培与鉴定专业的必修课,是一门新兴学科,可参考和借鉴的教学经验较少。其中的实验教学部分是促进我国现代中医药实践人才培养的重要环节,需要不断改革完善。针对教学中存在的问题,应从教师队伍建设、丰富实验类型、建立实验实训基地、改革教学模式、强化实验教学质量评价等方面进行改革,以实现教学目标。

Enemies atpeace:Recentprogressin Agrobacterium-mediated cereal transformation

Agrobacterium tumefaciens mediated plant transformation is a versatile tool for plant genetic engineering following its discovery nearly half a century ago.Numerous modifications were made in its application to increase efficiency,especially in the recalcitrant major cereals plants.Recent breakthroughs in transformation efficiency continue its role as a mainstream technique in CRISPR/Cas-based genome editing and gene stacking.These modifications led to higher transformation frequency and lower but more stable transgene copies with the capability to revolutionize modern agriculture.In this review,we provide a brief overview of the history of Agrobacterium-mediated plant transformation and focus on the most recent progress to improve the system in both the Agrobacterium and the host recipient.A promising future for transformation in biotechnology and agriculture is predicted.

园林植物遗传育种学课程思政教学探索与实践

课程思政在高校承担着实施立德树人使命的重要任务,而园林植物遗传育种学是园林专业中不可或缺的重点课程。该文以课程和专业特点为出发点,深入研究园林植物遗传育种学课程中蕴含的思政元素。着重强调如何将思政元素贯穿于整个园林植物遗传育种学课程中,通过有机融合专业理论与实际操作,使学生在掌握专业知识的同时提升综合素质。并对思政教学提出多角度的具体措施,包括优化教学体系、强化思政元素重点、多样的教学方法,落实思政目标以及完善教学考核和评分体系,旨在提高思政工作的质量。最终,为园林专业学生在未来工作中更好地应对复杂挑战,同时拥有崇高的价值观,为园林专业学生的综合素养培养奠定坚实基础。

农林类应用型专业课程教学实践与探索——以园林植物遗传育种学为例

园林植物遗传育种学是一门农林类应用型专业课程,该课程旨在介绍园林植物的遗传与育种原理、方法和技术,培养学生对园林植物育种的理论和实践能力。作为农林类应用型专业课程,应针对不同类型地方高校,不同专业背景和就业需求,进一步推进教学实践中理论与实践的结合,培养学生的实践能力和创新精神。

新农科背景下专升本园林植物遗传育种学课程教学改革研究

该文探讨新农科背景下专升本园林植物遗传育种学教学改革的重要性。针对当前教学中存在的问题,提出更新教学内容、多元化教学方法、加强实践教学、优化课程设置和加强教师队伍建设等改革方向和策略。通过这些措施的实施,可以更好地培养具备创新和实践能力的农业人才,适应新农科背景下对农业人才的需求,为现代农业的发展提供支持。

RAPD Assessment of Genetic Diversity of Yunjie(Eruca sativa Mill.)in China

Genetic diversity of Yunjie(.Eruca sativa Mill.)in China was assessed by analyses of RAPD(randomly amplified polymorphic DNA)markers. Twenty native cultivars representing Yunjie-growing eco-types in China were selected as material in this study. Twelve out of the 64 tested random decamer primers were able to identify 131 stable RAPD bands from these Yunjie cultivars. Of them 105 bands, or 80.15% of the total, were polymorphic. Most Yunjie cultivars from the same ecotype had their characteristic DNA bands. Cluster analysis by unweighted pair group method of arithmetic means(UPGMA)suggested that the 20 Yunjie genotypes could be divided into four groups. The genetic distances among the 20 cultivars varied from 0.117 8 between Shuozhou and Shenchi to 0. 499 4 between Hetian and Xiliang. Hetian alone could be a new type of Yunjie identified in China because it had the greatest genetic distance from all the other tested cultivars. These results indicate that Chinese Yunjie have abundant genetic diversity. Classification of Chinese Yunjie based on the RAPD information was in good agreement with the relationships between these Yunjie cultivars in their geographic origins and their plant morphology.

Genetic Parameters Estimates Associated to Conversion of Nicotine to Nornicotine in Burley Tobacco

Nicotine represents the predominant alkaloid in cultivated tobacco. In burley varieties, during senescence and curing of leaves, nicotine can be converted to nornicotine, which is highly undesirable because of its relationship with the tobacco specific nitrosamines formation. Thus, an alternative for producing varieties with low or null nornicotine content would be to select plants or progenies for traits related to nicotine conversion. Therefore, understanding genetic control and inheritance underlying this process is important to chooseappropriate strategies in breeding programs. Two contrasting inbred lines for nicotine conversion to nornicotine, TN 90 and BY 37, have been crossed to obtain the segregating generations (F2 and BCs). Genetic parameters of mean and variance, as well as the average degree of dominance and heritability were estimated. It has been found that nicotine conversion has predominantly additive effects, and in addition, narrow sense heritabilities at the individual level were higher than 65%. Both are desirable conditions for conducting a selection program of burley tobacco aiming at development of inbred lines associating yield and other traits with low or null nicotine conversion.

Adaptability, Stability and Multivariate Selection by Mixed Models

The aim of this work was to estimate the adaptability and stability of grain yield per hectare and percentage of crude protein of maize grains combined in an index, and to establish a multicharacter selection through mixed models based on an objective character and 15 auxiliary traits. The trials were conducted in the 2013/2014 agricultural year in four growing environments of the Rio Grande do Sul, BR state. The experimental design was randomized blocks arranged in a factorial scheme, being four growing sites × 15 single cross maize hybrids, arranged in three repetitions. The genotypic index, composed by the grain yield and the crude protein percentage in the grains, is the best selection strategy to achieve maize superior genotypes. The multivariate genotypes selection, considering grain yield and crude protein, is efficient. The genotypes FORMULA TL&reg;, AS1656PRO&reg;, P30F53Hx&reg;, LG6304YG&reg;and 30F53 are more adapted and stable for grain yield and percentage of crude protein, in the conditions of this study. The mixed models were efficient to employ the multicharacter selection and to contribute for maize genetic breeding.

Functional Role of miRNAs: Key Players in Soybean Improvement

Soybean(Glycine max(L.)Merr)is an agro-economic crop growing across the world to cater nutrition for both human and animal feed due to the high oil and protein content in its edible seeds.The genes and QTLs associated with important agronomic traits in this crop have already been identified and validated for soybean cyst nematode(SCN),Phytophthora root and stem rot,Pythium root rot and aphid resistance,seed quality,nutrient values,and also employed for genetic improvement in soybean.In the last decade,micro RNAs(miRNAs)have been considered the effector molecules,so the detection and characterization of novel miRNAs in soybean have been taken up by several workers.The advancement in the strategy of sequencing and tools of bioinformatics during last decade has contributed to the discovery of many soybean miRNAs,thus miRNA can be used as a tool in molecular breeding studies,and this has opened new vistas for miRNA mediated genetic improvement of soybean to augment crop productivity as well as nutritional quality.This review addresses the current state of understanding of miRNAmediated stress responses,nutrient acquisition,plant development and crop production processes in soybean.

Inheritance of the Anatomy--Morphological Structure of the Stalk by Interspecific Hybrids of the Glycine L.

The research focuses on the study of anatomical and morphological stalk structure ofsoya interspecific hybrids of the third generation （F3） between （Glycine max （L.） Merr.） and G. soja Sieb. et Zucc. in comparison with parent plant species. The parent plant species and interspecific hybrids were sowed and grew under similar conditions. The similarity of the anatomic structure of stalks of cultivated plants and Glycine soja （wild soya） proves the hypothesis the studied species have the same origin. However, the obtained results show the considerable degree of phylogenetic dissociation between the studied soya species. Interspecific hybrids inherit from G. soja the ability to high intensive growth. The G. soja use in practical selective breeding is of great interest.

2022年茶树遗传育种研究进展

文章总结概述了2022年度茶树遗传育种领域取得的主要进展。2022年度,科研工作者在茶树遗传育种领域取得了丰硕的成果,基于转录组、同源和异源转化、分子互作等研究手段,大量与茶树逆境胁迫抵御、功能物质代谢、生长发育调控相关的遗传分子机制及关键作用基因获得解析;茶树氨基酸含量、发芽期等性状相关的数量性状位点(QTL)被精细定位,为开发性状关联分子标记奠定了基础;62个茶树品种通过非主要农作物品种登记,5个品种授权获得植物新品种权,为茶产业高效发展提供了多样化的品种保障。

甜加糯玉米研究进展及发展对策分析

甜加糯玉米是我国首创的鲜食玉米新类型,综合了甜玉米和糯玉米优点,果穗上甜、糯粒随机相间排列,口感既甜又糯,近年来受到市场的热烈追捧,已成为鲜食玉米发展的趋势与重点。我国育种人员通过聚合玉米胚乳淀粉合成途径中的甜质基因和糯质基因,形成甜糯双(多)隐性自交系,再与糯玉米自交系或彼此间杂交组配,杂交后代产生显隐性基因分离,从而实现同一个果穗上同时出现甜、糯粒。甜加糯玉米的育种发展迅速,目前已构建起“传统育种方法(甜、糯玉米杂交组配法和甜加糯玉米二环系选育法)+现代育种手段(分子标记辅助选择技术和单倍体育种技术)”相结合的甜加糯玉米育种体系,育成品种向多样化、优质化、特色化、功能化方向发展。甜加糯玉米因产值高、生产周期短、可灵活搭配种植茬口,市场需求和种植面积逐年增加。然而由于存在种质资源遗传背景狭窄、繁殖和制种成本较高、品质评价体系尚不完善、保鲜加工技术亟待创新等制约因素,其面临的挑战也愈发凸显,阻碍了甜加糯玉米产业未来的发展。本文从甜加糯玉米育种理论基础、育种发展历程、品种审定情况、种植分布、种植模式和市场概况等方面进行阐述,探讨核心瓶颈及制约因素,并提出相应的对策建议,以期为甜加糯玉米育种研究和产业发展提供理论依据。