Study on Present Status of Plant Germplasm Resources Conservation and Countermeasures

Plant germplasm resources is the material foundation and key point for agricultural production, crop breeding and bioengineering. China is one of the centers for the origin of the cultivated plants worldwide, as well as one of the countries with most abundant plant resources and the highest biodiversity. Strengthening research in the conservation and utilization of plant germplasm resources is of significant value and importance. In this study, the present status of conservation, utilization, and existing problems of plant germplasm resources in China and around the world were reviewed; further, through analyzing measures taken by global countries for plant germplasm resources protection, countermeasures for plant germplasm resources conservation in China were also presented from three aspects, namely, collection and conservation, information network construction and national legislation and policies.

Research on Background and Utilization of Germplasm Resources in Maize

[Objective] The research aimed at introducing the background and utilization of germplasm resources in maize.[Method] The research progress on genetic background and utilization of maize germplasm resources was comprehensively reviewed in this paper,including maize heterotic groups and heterotic patterns,their flexible application in breeding and the utilization of various types of original materials.[Result] The results show that germplasm resource is the premise and basis for maize breeding.In-depth understanding and a reasonable selection of germplasm resources can significantly improve the breeding efficiency and speed up the breeding process.At the same time,it is considered that the selection and construction of original materials in maize breeding can not be limited to the heterotic groups and heterotic patterns,but has to be used reasonablely according to different types of germplasm resources and individual breeding objective and idea as well.[Conclusion] This study had broadened the idea and provided inspiration for the maize breeding practice in China.

Screening of Drought Stress Indicators and Analysis of Drought Resistance in Cultivated Rice Germplasm Resources in Guangxi

This study aimed to screen drought stress indicators and analyze the drought resistance in 105 cultivated rice germplasm resources in Guangxi Zhuang Autonomous Region under drought stress in the whole growth period based on D value of seven morphological traits including panicle neck thickness,effective panicle number per plant,1 000-grain weight,filled grain number per panicle,total grain number,seed setting rate and yield per plant.According to the results,under drought stress,yield per plant exhibited significant positive correlation with panicle neck thickness and exhibited extremely significant positive correlation with other five morphological traits.Based on the identification and evaluation of comprehensive drought-resistance index D value,seven highly drought-resistant cultivated rice varieties were screened,accounting for 6.67％.Upland rice germplasm resources in Guangxi Zhuang Autonomous Region possess strong drought-resistance capacity,which could be used to screen highly drought-resistant rice germplasm materials.This study provided material basis and theoretical reference for breeding drought resistant rice cultivars in Guangxi Zhuang Autonomous Region.

Research Progress on Germplasm Resources of Common Bean

The origin, classification, utilization and evaluation of germplasm resources, and breeding methods were introduced. The researches of biotic or/and abiotic stress, exploration of genomics and proteomics in common bean in recent years were reviewed in this paper, in order to provide theoretical reference for utilization and innovation of germplasm resources in common bean.

Fruit Anatomy of sect. Paracamellia with Reference to Their Significance of Germplasm Resources Exploitation

[Objective] To utilize the germplasm resources,new systematic evidence for the classification of sect.Paracamellia,genus Camellia is found in this article.[Method] Fruit anatomy of 10 species representing sect.Paracamellia was investigated.And the main component of sect.Paracamellia in the genus Camellia was studied by MVSP software.[Result] The exocarp was thin;mesocarp was broad,having a large number of stone cells;endocarp was lignified,and separated easily from seed.The principle components analysis suggested that the distance between species was far,showing far relation;the current study did not support the formation of Camellia grijsii（C.grijsii）and Camellia yuhsienensis（C.yuhsienensis）,Camellia shensiensis（C.shensiensis）should not be recognized as a variety of C.yuhsienensis.In addition,it also proved Ming＇s combining of Camellia confusa（C.confusa）and Camellia kissi（C.kissi）was unnatural.[Conclusion] The study provided theoretical basis for the development and application of sect.Paracamellia in the genus Camellia.

Study on Germplasm Resources of Tartary Buckwheat (Fagopyrum tataricum) in Shanxi Province

This study analyzed the tartary buckwheat recorded in the books Catalogue of Crop Germplasm Resources in Shanxi Province and Catalogue of Chinese Buckwheat Germplasm Resources by Excel 2003 and DPS 7.5 from the aspects of distribution areas,main agronomic traits and nutritional components,so as to lay a foundation for the selection of excellent buckwheat germplasm resources and improvement of buckwheat varieties.The results showed that different buckwheat varieties vary in plant height,node number of the main stem,grain weight per plant,grain weight per plant and kilo-grain weight.Compared with the national average values,buckwheat in Shanxi is higher in protein and fat,but lower in vitamin E and vitamin PP;it is rich in Ca,Mg,Cu,P,Se,Fe,Mn and Zn;and it contains 18 amino acids with the content of glutamic acid being the highest and the content of tryptophane being the lowest.After analyzing and classifying the tartary buckwheat germplasm resources recorded in Catalogue of Grop Germplasm Resources in Shanxi Province and Catalogue of Chinese Buckwheat Germplasm Resources,breeders could breed new varieties with high yield and quality and strong stress resistance by crossbreeding with these germplasm resources.

Morphological Diversity Analysis of Red-seed Watermelon (Citrullus lanatus ssp. vulgaris var. megalaspermus Lin et Chao) Germplasm Resources

[Objective] This study aimed to analyze the morphological diversity of red- seed watermelon （Citrullus lanatus ssp. vulgaris var. megalaspermus Lin et Chao） germplasm resources. [Method] Multiple cluster analysis and principal components analysis on the morphological traits of 51 red-seed watermelon germplasm resources were carried out. [Result] The coefficient of variations （CVs） of 39 morphological traits in 51 red-seed watermelon idioplasm resources ranged from 5.37% to 66.95%, with an average of 22.87%. The average of Shannon diversity information indices was 1.55. Among them, the Shannon diversity information index of seed length was the highest （2.16） and that of seed shell figure pattern was the lowest （0.32）. In ad- dition, the morphological diversity information indices of quantity characters were higher than that of quality characters. The principal components analysis revealed that the variance contribution rates of the first, second and third principal compo- nents were 19.49%, 15.32% and 9.55%, respectively. Cluster analysis divided the 51 materials into three broad branches based on the morphological traits. There was only one material in the fist branch and two in the second branch, and all the three materials were wild. The other 48 materials were divided into the third branch and all of them were cultivars. [Conclusion] This study provided a theoretical basis for the protection and utilization of red-seed watermelon resources.

Track Monitoring on Viability of Rice Germplasm Resources and Regeneration under Low Temperature Storage

53 rice germplasm resources warehoused during 1981-1984 were regarded as materials to monitor the viability at warehouse time and different years after warehoused. The results showed that seed germination rates of different rice germplasm resources assumed descending trend in storage, with annual decreasing rate between 0.12%-3.05% ; the seed germination rates of most cultivars were above 75% after stored for 26 years; forecasting analysis based on the germination rate of 75% as reference showed a huge difference of safe storage life for different rice germplasm resources, ranging from 12 to 50 years, even longer time. The results suggest that track monitoring on viability and regeneration of rice cultivars is of great importance for germplasm resources conservation.

Characterization of 124 Flue-cured Tobacco Germplasm Resources

[Objective] This study aimed to characterize 124 flue-cured tobacco germplasm resources, and to provide reference for making the best use of the existing flue-cured tobacco germplasm resources. [Method] A total of 124 flue-cured tobacco germplasm resources were studied via field experiment and statistic analysis to investigate characteristics of their growth period, morphologic characters, main agronomic traits, and economic characters. [Result] There were significant differences among the 124 flue-cured tobacco germplasm resources in growth period, morphologic characters, main agronomic traits, and economic characters. The coefficients of variation （CV） varied in a range of 7.9%-22.5%. Among them, CV of bud stage was higher, and that of corolla length was lower. Many germplasm resources were attacked seriously by black shank disease at the end of field experiment, including those with disease index higher than 90, like Kutsaga 110, TI706, Ky 151, KM10, Longshe, Chaoxian Kangchi, Kutsaga 51E, Yongding No.1, and those with disease index among 75-90 such as Liaoyan No. 8, Lingnong No.2, Shandong Duoye, 581, Cunjingyan, KRK26, and Special 400. The tobacco root knot nematode invasion was light in some germplasm or never happened in other germplasm resources. TMV happened sporadically. CV 87, Yunyan 99, Yunyan 85, K326, Yunyan 87, Zhubuo No.1, T64 and T66 produced higher yield, production value, proportion of good leaves and sold at a higher price. Finally, we screened out the germpalsm resources with good comprehensive economic values and high disease resistance such as CV 87, Yunyan 99, Yunyan 85, K326, Yunyan 87, Zhubuo No.1, T64, T66, Honghuadajinyan, G-28, Taiyan No. 8, 77089-12, Yunyan 97, K346, V2, K149, NC567, NC297, Yunyan 201, Yunyan 203, KRK22. [Conclusion] This study provides reference for making better use of tobacco germplasm resources, and breeding new varieties.

Documentation Concordance,Sharing and Utilization of Tea Germplasm Resources in Yunnan

In this paper,the research achievements and progress of Yunnan tea germplasm resource in past sixty years are systematically reviewed from the following aspects：exploration,collecting,conservation,protection,identification,evaluation and shared utilization.Simultaneously,the current problems and the suggestions about subsequent development of tea germplasm resources in Yunnan were discussed,including superior and rare germplasm collection,tea genetic diversity research,biotechnology utilization in tea germplasm innovation,super gene exploration and function,the construction of utilization platform,biological base of species and population conservation.

Evaluation and Screening of Aceraceae Germplasm Resources

[Objective] The aim was to screen out excellent Aceraceae germplasm resources which can be applied in gardens and urban landscape. [Method] The set of 17 biological traits of 24 Aceraceae species were observed and recorded. Taking into consideration aesthetic evaluation of different groups of people, the studied species were graded in quantitative scale. The species with higher overall score is considered better germplasm resource. [Result] The Aceraceae species with top ten highest overall scores were： Acer japonicum ＇Aconitifolium＇ （45.5）, Acer palmatum var. thunbergii （43.8）, Acer palmatum （41.8）, Acer elegantulum （39.2）, Acer elegantulum var. macrurum （39.2）, Acer rubrum （39.1）, Acer Cordatum（38.8）, Acer truncatum （38.3）, Acer olivaceum （37.7） and Acer acutum （37.3）. [Conclusion] The above ten species can be used preferentially as excellent Aceraceae germplasm resources for landscaping.

RAPD Analysis of Germplasm Resources of Kudingcha Species in Oleaceae

The random amplified polymorphic DNA marker （RAPD） was applied to detect the genetic relationships and diversity among 21 germplasm materials of Kudingcha species in Oleaceae, which involved 8 species, i.e., Ligustrum robustum （Roxb.） Blume, L. henryi Hemsl., L. japonicum Thunb, L. japonicum Thunb. var. pubscens Koidz, L. lucidum Ait., L. pedunculare Rehd, Osmanthus masumuranus Hayata, and L. delavayanm Hariot. 20 RAPD primers selected were applied for the amplification on the 21 germplasm materials mentioned above. 427 bands were obtained, and the percentage of polymorphic bands （PPB） was 97.7%. The genetic similarity coefficients （GS） ranged from 0.1522 to 0.8322 with an average of 0.5466. There was a significant genetic difference among germplasm materials of Kudingcha species in Oleaceae, and UPGMA cluster based on the GS of RAPD could distinguish all test germplasm materials clearly and indicated the relationship of the 8 species mentioned above, all of which indicated that RAPD markers could be used for the studies of genetic diversity and relationship and classification of germplasm resources of Kudingcha species in Oleaceae. Analysis results of RAPD showed that L. japonicum Thunb. var. pubscens Koidz has closer genetic relationship with L. pedunculare Rehd and further genetic relationship with L. japonicum Thunb. among all tested species. The authors suggest that further research is needed to study whether L. japonicum Thunb. var. pubscens Koidz should be classified into a variata of L. japonicum Thunb, or should be considered as an independent species. The analysis results supported that L. pururascens Y. C. Yang should be combined into L. robustum （Roxb.） Blume.

Wild Soybean Germplasm Resources Conservation and Use in Shandong Province

Glycine soja or wild soybean is the wild ancestor of the soybean, being an important source for property improvement and variety breeding. With abundant wild soybeans, their habitat is undermining, and wild soybeans are facing increasing- ly threatened in Shandong if measures are not taken yet. Besides, wild soybean germplasm is far from further exploiting or using. The research analyzed status quo and problems of wild soybean germplasm posed countermeasures or suggestions in crop germplasm conservation and use. resources conservation and use and pro- order to provide references for agricultural crop germplasm conservation and use.

Safe conservation and utilization of peanut germplasm resources in the Oil Crops Middle-term Genebank of China

Peanut(Arachis hypogaea L.)is an important oil and cash crop in the world.Peanut germplasm collected in China are abundant,which provides important material guarantee for peanut breeding and industrial development.Here,the safe conservation technology and indicators of peanut germplasm resources in the Oil Crops Middleterm Genebank of China were expounded from three processes of storage,monitoring,reproduction and renewal.We summarized and reviewed the situation of conservation and utilization of peanut germplasm resources in the Middle-term Genebank in the past 20 years.The future research direction of peanut resources in the Oil Crops Middle-term Genebank of China is prospected.

In vitro Screening of Fusarium Wilt-resistant Germplasm Resources of Red Edible Seed Watermelon( Citrullus lanatus ssp. vulgaris var. megalaspermus Lin et Chao)

[ Objective] This study aimed to establish an appropriate technology system for in vitro screening of Fuzarium wilt-resistant germplasm resources of red edible seed watermelon and obtain variants resistant to fusaric acid, thus providing resistant materials for breeding Fusarium wilt-resistant red edible seed watermel- on. [ Method] Using Zhongxin No. 1 red edible seed watermelon advemitious buds as screening materials and fusaric acid （FA） as a stress agent, in vitro screen- ing of Fusarium wilt-resistant red edible seed watermelon clonal variants and identification of Fusarium wilt-resistance of the germplasm resources of red edible seed watermelon were performed. [ Result] The results showed that the appropriate FA for in vitro screening of Fusarium wilt-resistant red edible seed watermelon vari- ants was 15 mg/L. In vitro screening system for Fusarium wilt-resistant red edible seed watermelon variants was established preliminarily and FA-resistant regenera- ted plants were obtained. Among the 36 germplasm resources of red edible seed watermelon, there were 2 highly resistant materials, 6 moderately resistant materi- als, 11 slightly resistant materials and 17 highly susceptible materials. [ Conclusion] This study confirmed preliminarily that in vitro screening method is effective for obtaining resistant materials of red edible seed watermelon.

Screening of Sapindus germplasm resources in China based on agro-morphological traits

Sapindus L.species are widely cultivated for biodiesel,biomedical,and biochemical raw materials in southern China.However,yields fuctuate widely due to the lack of high-yielding,high-quality,stable cultivars.Therefore,the objectives of this study were to evaluate three species and one variety among 149 nationwide Sapindus species and screen for elite accessions which would serve as Sapindus breeding materials.Accessions were evaluated on 19 agro-morphological traits by correlation analysis and principal component analysis.These displayed substantial diversity and a broad range of economic traits.In particular,accessions of Sapindus mukorossi and Sapindus rarak had more variation in economic traits than Sapindus delavayi and Sapindus rarak var.velutinus.Increased saponin accumulation may be achieved at the cost of seed oil production.Thirty elite accessions for oil and saponin production,and for comprehensive utilization were screened and accessions no.80,110,and 112 had significant potential to produce high yields.These elite accessions will facilitate the identification of genetic determinants of valuable traits and the effective utilization of trait variability in Sapindus breeding.

Progress of the Research on the Conservation of Crop Germplasm Resources in China

In the last 20 years, China has made considerable achievements in the conservation of crop germplasm resources. A network for crop germplasm conservation has been established by the end of 2002, which includes a national long-term seed genebank and its duplicated genebank, 8 national medium-term seed genebanks, 30 national field genebanks. 2 national in vitro genebanks, and 3 in situ conservation sites including 1 for wild soybean and 2 for wild rice. More than 334 000 crop germplasm accessions are currently stored in the national long-term genebank, covering 35 families, 192 genera and 712 species, which rank in the first place in the world. More than 43 000 accessions of vegetatively propagated crops and perennial crops covering more than 900 species are conserved in the national field genebanks. In addition, 2 300 accessions are stored in the national in vitro genebanks. This paper reviewed the latest advances of techniques for safety preservation of stored germplasm in seed genebank, ultra-dried seed storage and in vitro preservation in China and discussed current highlights in germplasm conservation.

Discrimination of Wild Tea Germplasm Resources (Camellia sp.) Using RAPD Markers

Discrimination of 24 wild tea germplasm resources (Camellia sp.) using RAPD markers was conducted. The result showed that RAPD markers were very effective tool and method in wild tea germplasm discrimination. There were 3 independent ways to discriminate tea germplasms, a) unique RAPD markers, b) specific band patterns and c) a combination of the band patterns or DNA fingerprinting provided by different primers. The presence of 16 unique RAPD markers and the absence of 3 unique markers obtained from 12 primers made it possible to discriminate 14 germplasms. Using the unique band patterns of primer OPO-13 could discriminate 10 tea germplasms. It was of much importance using minimum primers to obtain maximum discrimination capacity. All the 24 wild tea germplasms could be discriminated easily and entirely by the band patterns combination or DNA fingerprinting obtained from OPO-13, OPO-18, OPG-12 and OPA-13, including two wild tea trees of very similar morphological characteristics and chemical components.

Report on Screening Test of Dazhou Superior Ramie Germplasm Resources

[Objectives]To promote the development of the ramie industry in Dazhou City of Sichuan Province and provide a material basis for the breeding of new ramie varieties.[Methods]The Institute of Bast Fiber Crops of Dazhou Academy of Agricultural Sciences performed a screening test of excellent ramie germplasm resources from 2017 to 2019 to compare the growth,resistance,raw fiber yield and fiber fineness of the experimental materials.[Results]All the experimental materials showed strong growth potential,drought resistance and disease resistance.There were 8 kinds of resources with a fiber fineness greater than 2000 m/g,of which 3 kinds of resource materials had a fiber fineness greater than 2300 m/g;12 kinds of resources has the raw fiber yield exceeding the control and 10 kinds of resources had the raw fiber yield≥2000 kg/ha;3 kinds of resources met the requirements of the high-yield and high-quality indicators(fiber fineness exceeding 2000 m/g and raw fiber yield≥2000 kg/ha),they were BD0718,BD1614 and BYL2.[Conclusions]These high-quality ramie resources can provide a rich resource base for the breeding of new ramie varieties.

A Study on the Phenotypic Genetic Diversity of Camellia Germplasm Resources in Macheng City

The genetic diversity analysis was done on 11 phenotypic traits of 35 camellia germplasm materials. The results showed that there were varying degrees of variation in 11 traits concerning the flowers and leaves selected in this study,and petal number had the largest coefficient of variation,followed by ovary height,and leaf length had the smallest coefficient of variation. F test results showed that the differences in 11 phenotypic traits reached a significant level. Through the trait correlation analysis,it was found that there was a positive or negative significant correlation between the 11 phenotypic traits. Principal component analysis results showed that the cumulative contribution rate of the first three principal components was 71. 185%,the eigenvector which reflected flower pattern was largest,and flower pattern had a great impact on classification of camellia variety. Based on the genetic differences in traits between varieties,the 35 test materials were divided into three categories: Group I was characterized by large flower pattern; Group II was characterized by large leaf pattern; Group Ⅲ was characterized by many petals. Flower diameter and flower height were important standards for classification of camellia variety.