Acid detergent lignin,lodging resistance index,and expression of the caffeic acid O-methyltransferase gene in brown midrib-12 sudangrass |
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Authors: | Yuan Li Guibo Liu Jun Li Yongliang You Haiming Zhao Huan Liang Peisheng Mao |
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Institution: | 1.Department of Grassland Science, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China;2.Dryland Farming Institute, Hebei Academy of Agricultural and Forestry Sciences, Hengshui 053000, China;3.Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China;4.Department of Animal Science, Southwest University, Chongqing 400715, China |
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Abstract: | Understanding the relationship between acid detergent lignin (ADL) and lodging resistance index (LRI) is essential for breeding new varieties of brown midrib (bmr) sudangrass (Sorghum sudanense (Piper) Stapf.). In this study, bmr-12 near isogenic lines and their wild-types obtained by back cross breeding were used to compare relevant forage yield and quality traits, and to analyze expression of the caffeic acid O-methyltransferase (COMT) gene using quantitative real time-PCR. The research showed that the mean ADL content of bmr-12 mutants (20.94 g kg−1) was significantly (P < 0.05) lower than measured in N-12 lines (43.45 g kg−1), whereas the LRI of bmr-12 mutants (0.29) was significantly (P < 0.05) higher than in N-12 lines (0.22). There was no significant correlation between the two indexes in bmr-12 materials (r = −0.44, P > 0.05). Sequence comparison of the COMT gene revealed two point mutations present in bmr-12 but not in the wild-type, the second mutation changed amino acid 129 of the protein from Gln (CAG) to a stop codon (UAG). The relative expression level of COMT gene was significantly reduced, which likely led to the decreased ADL content observed in the bmr-12 mutant. |
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Keywords: | acid detergent lignin brown midrib dry matter lodging resistance index sudangrass |
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