Statistic Analysis on Quantitative Characteristics for Developing the DUS Test Guideline of Ranunculus asiaticus L.

Selection of quantitative characteristics, division of their expression ranges, and selection of example varieties are key issues on developing DUS Test Guidelines, which are more crucial for quantitative characteristics since their expressions vary in different degrees. Taking the development of DUS Test Guideline of Ranunculus asiaticus L. as an example, this paper applied statistic-based approaches for the analyses of quantitative characteristics. We selected 9 quantitative characteristics from 18 pre-selected characteristics, based on within-variety uniformity, stability between different growing cycles, and correlation among characteristics, by the analyses of coefficient of variation, paired-samples t-test and partial correlation. The expression ranges of the 9 selected quantitative characteristics were divided into different states using descriptive statistics and distribution frequency of varieties. Eight of the 9 selected quantitative characteristics were categorized as standard characteristics as they showed one peak in distribution frequency of 120 varieties in various expressions of the characteristics, whereas, plant height can be categorized as grouping characteristic since it gave two peaks, and can group the varieties into pot and cut varieties. Finally, box-plot was applied to visually select the example varieties, and varieties 7, 12, and 28 were determined as the example varieties for plant height. The methods described in this paper are effective for the selection of quantitative characteristics, division of expression ranges, and selection of example varieties in Ranunculus asiaticus L. for DUS test, and may also be interest for other plant genera.

Preparation of the UPOV Guidelines for the Conduct of Tests for Distinctness, Uniformity and Stability–Tea Plant [Camellia sinensis (L.) O. Kuntze]

Distinctness, Uniformity and Stability （DUS） testing is the technical base of Plant Variety Protection （PVP） and the scientific basis for the approval of Plant Breeder＇s Rights （PBR）. DUS Test Guidelines are not only the technical manuals for the DUS testing authorities to conduct the testing, but also the technical standards for the competent authorities to examine the DUS of new varieties of plants. Tea plant, originated from Yunnan Province, China, is a very important woody cash species in the world. The International Union for the Protection of New Varieties of Plants （UPOV） DUS Test Guidelines for tea plant is the first Test Guidelines prepared by China for the UPOV. In this article, the subject, selection, and determination of characteristics, states of expression of characteristics and the selection of example varieties, assessment of the UPOV DUS Test Guidelines for tea plant were elucidated in detail. Finally, the proposal of PVP for tea plant in China was also proposed. The preparation of UPOV DUS Test Guidelines for tea plant will have important significance both for promoting the development of PVP and increasing the status of international PVP fields for China.

Characters Selection and Assessment for Spathiphyllum DUS Testing Guideline

[Objectives]This study was conducted to provide technical standards for domestic Spathiphyllum variety description and resource evaluation.[Methods]Through field trials and character surveys of the collected 83 Spathiphyllum varieties,after several revisions by fellow experts,and with reference to the Guidelines for Testing the Specificity,Consistency and Stability of New Plant Varieties:Spathiphyllum(TG/135/3)issued by the International Union For The Protection of New Varieties of Plants,the DUS testing guidelines for Spathiphyllum have been developed,and statistical analysis and other methods were used to study the traits for the guideline.[Results]Thirty two testing traits,including 11 mandatory traits,8 basic traits,10 new traits,and 3 optional traits were finally determined;five traits including plant height,plant width,and leaf length were divided into 7 grades,and 9 traits such as leaf width,spathe length,and spathe width were divided into 5 levels;and the observation method and trait code of the trait spathe depth were adjusted.[Conclusions]The development of this guideline provides a basis for judging the specificity,consistency and stability of Spathiphyllum varieties,and is of great significance to the breeding and protection of Spathiphyllum varieties.

Endocrine Disruption of Cadmium in Rats Using the OECD Enhanced TG 407 Test System

Objective To evaluate the endocrine disrupting effects of cadmium （Cd） using OECD enhanced TG407 test guideline. Methods Sprague-Dawley （SD） rats were randomly divided into six groups and accordingly administered with 0, 1, 2.5, 5, 10, 20 mg/kg.BW/day of Cd by gavage for 28 days. Body weight, food consumption, hematology, biochemistry, sex hormone levels, urinary β2-microglobulin, organ weights and histopathology and estrous cycle were detected. Results Cd could significantly decrease animals＇ body weight （P〈0.05）. Serum luteinizing hormone （LH） at 10-20 mg/kg.BW groups and testosterone （T） at 2.5 and 10 mg/kg.BW groups decreased significantly （P〈0.05）. However, no statistically significant change was found in urinary β2-microglobulin among Cd-treatment groups （P〉0.05）. Endpoints related to female reproduction including uterus weight and histopathological change at 10-20 mg/kg.BW groups showed significant increase （P〈0.05）. While among male rats in 2.5, 10, 20 mg/kg.BW groups, weight of prostate, thyroids, and seminal vesicle glands significantly decreased （P〈0.05）. Moreover, no histopathological change was observed in kidney. Conclusion Results suggested that Cd can cause endocrine disrupting effects in SD rats. Comparing with possible renal toxicity of Cd, its toxicity on endocrine system was more sensitive.