3.5 | Phylogenetic analyses of the nuclear geneDMC1 and the chloroplast gene rps16 sequences
In order to analyze the possible parents of the hybrids, we analyzed the nuclear gene DMC1 and the chloroplast gene rps16 sequences of the hybrids and their associated species of Roegneria andElymus. The length of DMC1 sequences of hybrids ranged from 998 to 1004bp. The data matrix contained 1166 characters, of which 267 characters were variable and 235 were parsimony informative. A single phylogenetic tree generating by maximum likelihood analysis using the TPM1uf + G model (−Ln likelihood = 4547.37) was shown in Figure 8. The phylogenetic analyses of the DMC1 sequence were shown in Figure 8. In clade I (BS=54%, PP=0.97), the St-type sequences formed a strongly supported clade, which included diploidPseudoroegneria (St) species, tetraploid Elymus(StH) and Roegneria (StY) species and hybrids. The St-type sequences of 15 hybrids and R. turczaninovii(StY) formed a subclade (BS=51%, PP=1.00). In clade Ⅱ (BS=99%, PP=1.00), the Y-type sequences formed a strongly supported clade, which contained the tetraploid species ofRoegneria (StY) species and hybrids. The Y-type sequences of 15 hybrids, R. turczaninovii (StY) andR. stricta (StY) formed a subclade (BS=64%, PP=0.83). In clade Ⅲ (BS=96%, PP=1.00), the H-type subclade included diploidHordeum species and tetraploid Elymus (StH) species. Clade IV (BS=96%, PP=1.00). other clade included 10 diploid species containing 10 different basic genomes (Ee, Eb,W, P, Ta, V, Ns,A, B, and D) In order to explore the maternal origin of the hybrids identified cytologically, rps16 sequence was selected for phylogenetic analysis. The length of hybrids rps16 sequences varied from 830 to 831bp. A lot of 28 sequences were selected for ML analysis.Bromus sterilis were used as the outgroup. The data matrix contained 881 characters, 30 were variable characters and 30 were parsimony informative. TIM1 + G as the best-fit model (−Ln likelihood = 1555.21) was used in phylogenetic analysis. The ML tree was displayed in Figure 9. The phylogenetic analyses of the rps16 sequence were shown in Figure 9. The rps16 sequences from hybrids RH1 were grouped withR. stricta (BS=64%, PP=0.97). The clade contained 5 hybrids RH1 sequences and R. stricta. The rps16 sequences from hybrids RH2 were grouped with R. turczaninovii (BS=88%, PP=1.00). The clade contained 10 hybrids RH2 sequences and R. turczaninovii. The above results showed that R. stricta was the maternal donor of the hybrids RH1, R. turczaninovii was the maternal donor of the hybrids RH2.