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.

Relationship Between Resistance Gene Analogue and Blast Resistance in Rice

DNA fragments of 43 rice varieties were amplified with 11 pairs of primers designed based on resistance gene analogue （RGA） of plants, and the blast resistance of the varieties was identified by inoculation with 33 isolates of Magnaporthe grisea collected from Yunnan Province, China. Clustering results revealed a significant correlation between the blast resistance and DNA bands with a correlation coefficient of 0.6117 （α=0.01）, indicating that the resistance analysis based on RGA-PCR clustering analysis coincided with that based on inoculation. The correlation coefficients, ranging from 0.1701 to 0.535, however, depended on the primers. Five pairs of primers, S1/AS3, S1 INV/S2 INV, XLRR For/XLRR Rev, Pto-Kinl IN/Pto-Kin2 IN, and NLRR For/NLRR Rev might be applied for blast resistance identification in consideration of their band numbers and polymorphisms, and their correlation coefficients with blast resistance were 0.5305, 0.4898, 0.4059, 0.3719 and 0.3524, respectively. Besides, indica and japonica rice except two highly susceptible varieties, CO39 and Lijiangxintuanheigu could be well classified by the 11 pairs of primers.

Genetic Diversity and Genetic Structure of Maize Inbred Lines from Yunnan Revealed by SNP Chips

[Objectives]The genetic diversity and population genetic structure of 107 inbred lines of maize in Yunnan were analyzed,in order to provide technical support for maize germplasm innovation,genetic improvement of germplasm resources,variety management,and lay a solid foundation for exploring genes related to fine traits in the future.[Methods]The 107 maize inbred lines generalized in Yunnan were selected,and 45 backbone inbred lines commonly used in China were used as reference for heterotic group classification.On Axiom Maize 56K SNP Array platform,maize SNP chips(56K)were used to scan the whole maize genome,and the NJ-tree model of Treebest was used to construct a phylogenetic tree.Principal component analysis(PCA)was conducted by GCTA(genome-wide complex trait analysis)to reveal the genetic diversity and population genetic structure.[Results]In the 107 Yunnan local inbred lines,5533 uniformly distributed high-quality SNP marker sites were finally detected.Based on the analysis of these SNP marker sites,Nei s gene diversity index(H)of 107 maize germplasm genes was 0.2981-0.5000 with an average value being 0.4832,and polymorphism information content(PIC)values were 0.2536-0.3750 with an average value being 0.3662.The minimum allele frequency value was 0.5000-0.8178 with an average value being 0.5744.The analysis of population genetic structure showed that when K=6,the maximum value of△K was the maximum,which meant that the inbred lines used in this study could be divided into six groups.They were Tangsi Pingtou blood relationship group,PB blood relationship group,335 female blood relationship group,Zi 330 and the Lüda Honggu blood relationship group,unknown group 1 and unknown group 2.No inbred lines were divided into other heterotic groups.Among them,37 inbred lines from the 2 unknown groups could not be classified into the same group as the 10 known heterotic groups in China.The results of principal component analysis showed that the 107 maize inbred lines generalized in Yunnan could be clearly distinguished from the backbone maize inbred lines commonly used in China.Most of the maize inbred lines in Yunnan were concentrated near the reference backbone inbred lines.But some Yunnan inbred lines were far away from the reference inbred lines commonly used in China.[Conclusions]The maize germplasm resources in Yunnan area were rich in genetic diversity,including multiple heterotic groups,and there was a rich genetic basis of breeding parents.They could be clearly distinguished from the backbone inbred lines commonly used in China,and some of them had a long genetic distance from the backbone inbred lines.The resources which have good application potential can be used to create new heterotic groups.