Screening On Natural Mixed Progenies Excellent Individual And Identification Of The Offspring’s Male Parent In Miscanthus Lutarioriparius Tetraploid

Miscanthus lutarioriparius,a perennial C4 grass tall herbaceous plant,is a domestic species in China.Characteristics with high biomass yield and high cellulose content make it becomes one of the most promising fiber-based energy plants.Meanwhile,it is also a kind of plant resources with both economic and ecological value,which has attracted much attention in domestic and foreign scientists.At the same time,because polyploidy plants usually show better tolerance to abiotic and biotic stress,high biomass yield,the creation of M.lutarioriparius polyploids has become an important direction for the cultivation of new germplasm of M.lutarioriparius.In this study,sexual offspring of M.lutarioriparius tetraploid had been selected as the experiment materials.The SLAF simplified genome sequencing technology,genetic relationship analysis and principal component analysis were used to identify the sexual offspring is hybrid authenticity;10 M.lutarioriparius triploid lines were selected from the progeny population to reproduction by underground rhizomes.The agronomic traits such as stem length,single stem dry weight and relative water content of 10 triploid lines were tested through random block planting experiments for three consecutive years.After testing the cellulose content and mineral element content of the experimental lines,10 M.lutarioriparius triploids were evaluated comprehensively according to their agronomic characteristics.The main results are as follows:(1)Using the SLAF technique,800,081 SLAF tags were developed in 50 species of Miscanthus(19 samples of hybrids,1 sample of the female parent and 30 candidates of the male parents),including 160,368 polymorphic SLAF tags and 469,509 SNP markers.The results showed that the most likely male parent of the polyploid population was M.lutarioriparius C3 through genetic analysis of developed SNP markers,and the polyploid population of M.lutarioriparius was a real hybrid population.(2)The data analysis of agronomic traits in 10 triploid M.lutarioriparius lines were carried out by variance analysis.The results showed that agronomic traits had highly significant differences(P<0.01)between different years and 10 genotypes,which indicated that agronomic characters of these tested lines varied with different growth ages and species.The quality characteristics of all materials in 2018 had been measured,the results revealed that the content of cellulose and lignin was 26.94% ～ 51.13% and 33.1% ～ 44.3% respectively,and there were no significant differences between different materials.The content of hemicelluloses was 14.8% ～ 43.57%and there were significant differences between different materials.The contents of all mineral elements were: K was 1719.70～4654.30 mg/kg,Na was 31.00～280.200 mg/kg,Ca was 1115.90～3773.20 mg/kg,Mg was 288.40～1213.10 mg/kg,P was 409.20～1755.50 mg/kg,Chlorine was 627.00～3486.00 mg/kg,Nitrate was 158.50～791.00 μg/g,Sulfate was 33.80～248.00 mg/L.There were no significant differences in the content of other mineral elements in all tested lines except Sulfate.According to the comprehensive scores of agronomic characters of all genotypes and principal component analysis of mineral elements,the results showed the comprehensive scores of 10 tested lines ranked as follow: D3 > D6 > L10 > D1 > D15 > D11 > D5 > D12 > D4 > D9;This manuscript provided theoretical support for the development of high yield molecular markers and molecular marker assisted breeding of M.lutarioriparius;it laid an elementary foundation for the breeding of polyploid cultivars and the further development of high yield germplasm of M.lutarioriparius in the future.