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Acta Prataculturae Sinica ›› 2018, Vol. 27 ›› Issue (11): 67-76.DOI: 10.11686/cyxb2017506

• Orginal Article • Previous Articles     Next Articles

QTL analysis of nine biomass-related traits in tetraploid orchardgrass using ultra-high-density genetic mapping

TANG Lu, HUANG Lin-kai, ZHAO Xin-xin, ZHANG Xu, NIE Gang, ZHANG Xin-quan*, MA Xiao   

  1. Animal Science and Technology College, Sichuan Agricultural University, Chengdu 611130, China
  • Received:2017-12-13 Revised:2018-04-28 Online:2018-11-20 Published:2018-11-20

Abstract: We have identified the QTLs(quantitative trait locus) of biomass-related traits in tetraploid orchardgrass in order to improve selection efficiency for good yield genotypes and to provide a basis for molecular-assisted breeding. The test materials used were a hybrid offspring population consisting of 214 individuals from a cross of two cultivars, ‘Kaimo’ (female parent) and ‘01436’ (male parent). In 2014, phenotypic identification and correlation analyses were carried out on nine biomass-related traits in two different habitats, Hongya and Baoxing. Based on the integrated map, the QTLs of nine biomass-related traits were analyzed using MapQTL 5.0: plant height (PH), flag leaf length (FLL), second leaf length (SLL), flag leaf width (FLW), secondleaf width (SLW), stem diameter (SD), inflorescence length (IL), tiller number (TN) and dry weight per plant (DW). Results indicated that most of the traits showed significant differences between parents and followed the normal distribution of continuous variation among populations, conforming with the hereditary characteristics of quantitative traits. Correlation analysis showed that most of the traits were significantly positively correlated with dry weight. The highest correlation with plant dry weight was tiller and plant height. A total of 60 QTLs were identified and distributed into 5 linkage groups (except for LG6 and LG7), with genetic contribution ranging from 5.7%-24.7%. For all of the 60 QTLs, the numbers for controlling plant height, flag leaf length, second leaf length, flag leaf width, second leaf width, stem diameter, inflorescence length, tiller number and dry weight per plant were 12, 15, 4, 2, 2, 4, 12, 3 and 6 respectively.

Key words: orchardgrass, biomass related traits, QTL analysis