He Fang, Bao Yinguang, Qi Xiaolei, Ma Yingxue, Li Xingfeng, Wang Honggang
State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian 271018, People's Republic of China.
J Genet. 2017 Mar;96(1):165-169. doi: 10.1007/s12041-017-0754-2.
Thinopyrum ponticum (2n = 70) serves as a valuable gene pool for wheat improvement. Line SN0224, derived from crosses between Th. ponticum and the common wheat cultivar Yannong15, was identified in the present study. Cytogenetic observations showed that SN0224 contains 42 chromosomes in the root-tip cells and 21 bivalents in the pollen mother cells, thereby demonstrating its cytogenetic stability. Genomic in situ hybridization, probed with the total genomic DNA of Th. ponticum, produced hybridization signals in the distal region of two wheat chromosome arms. After inoculation with the Blumeria graminis f. sp. tritici (Bgt) isolates, SN0224 exhibited immunity. Segregation in F1s and F2s from the cross SN0224/cv. Huixianhong indicated that SN0224 carries a single dominant gene for powdery mildew (Pm) resistance, which was temporarily designated PmSn0224. Three markers Barc212, Xwmc522 and Xbarc1138 were detected to be linked with PmSn0224. Based on the locations of the markers, PmSn0224 was located on the chromosome 2A. None of the three markers above is linked with the previously reported PM resistance genes on chromosome 2A, and none of the previously reported PM resistance genes on chromosome 2A is related to Th. ponticum. Therefore, PmSn0224 is likely a novel gene putatively from Th. ponticum.
蓬柄麦（2n = 70）是小麦改良的宝贵基因库。本研究鉴定了由蓬柄麦与普通小麦品种烟农15杂交衍生而来的品系SN0224。细胞遗传学观察表明，SN0224根尖细胞含有42条染色体，花粉母细胞含有21个二价体，从而证明了其细胞遗传学稳定性。以蓬柄麦的总基因组DNA为探针进行基因组原位杂交，在两条小麦染色体臂的远端区域产生了杂交信号。接种小麦白粉病菌（Bgt）分离株后，SN0224表现出免疫性。SN0224/品种辉县红杂交后代F1和F2的分离表明，SN0224携带一个抗白粉病（Pm）的显性单基因，暂时命名为PmSn0224。检测到三个标记Barc212、Xwmc522和Xbarc1138与PmSn0224连锁。根据标记的位置，PmSn0224位于2A染色体上。上述三个标记均与先前报道的2A染色体上的抗白粉病基因不连锁，且先前报道的2A染色体上的抗白粉病基因均与蓬柄麦无关。因此，PmSn0224可能是一个推测来自蓬柄麦的新基因。
