Abstract:Based on 2,256 common wheat reference varieties for DUS test in China, a DNA profile database was established to assist in distinctness test. We first analyzed the DNA profiles of 96 reference varieties using 81 fluorescently labeled SSR markers. A total of 731 alleles were detected with the number of alleles varying between 3 and 16 and the PIC values from 0.24 to 0.82. A DNA profile database consiting of 2256 wheat reference varieties was constructed using 42 fluorescently labeled SSR markers. A total of 148,493 datapoint were included with amissing rate of less than 5%. The genetic and genotypic datasets of 176 wheat varieties were collected and analyzed. The genetic similarities between the non-distinct candidate varieties and their most similar vairieties were above 90%. The candidate varieties with a genetic similarity of over 80% are assumed to be similar varieties, which are suggested to be further investigated for phenotypic variations in the field.

Abstract:Compliance with distinctness, uniformity and stability requirements is a precondition for granting of plant breeder’s rights and variety registration. Similar varieties screening is a key technical step for distinctness test. In this study, charecteristics of 3696 varieties (incuding single cross hybrids and inbred lines) from Huang-huai-hai Region planted in 6491 plots from different years at a single location were observed and recorded according to maize DUS test guildlines. After data collation and conversion of mearurments into notes, a database composed of charateristics data of 3696 varietis was constructed. Based on the investigation of variation of observations of state of expressions for the characteristics, the range of notes for 27 charactristics was determined and the charateristics were classified into four classes accordingly. A similar variety screening method was developed based on the deternined range of notes for each charateristic using the characteristics database. This method improves the effciency and stringency of similar variety screening using phenotypic characteristics.

Abstract:Distinctness, uniformity and stability (DUS) of plant variety is one of prerequisites for granting Plant Breeders’ Rights. DUS test guidelines is the technical basis for DUS testing. In this paper, the process of the development of test guidelines for Job’s tears, including the subject, quantity requirements of propagation materials, selection of characteristics, identification of states of expression, screening of example varieties, assessment criteria of DUS and the design of technical questionnaire were elaborated. The development of DUS test guidelines for Job’s tears will contribute to improve plant variety protection, promote variety innovation and strengthen variety management for Job’s tears.