采用随机区组试验,对不同除草剂不同用量处理下的谷子不同生育期株高、穗质量、穗粒质量及理论产量进行取样调查,为春谷谷田除草剂的安全使用提供科学依据。结果表明,苗前使用38%莠去津1 500~2 250 m L/hm2对植株株高影响较小,用量为2 2...采用随机区组试验,对不同除草剂不同用量处理下的谷子不同生育期株高、穗质量、穗粒质量及理论产量进行取样调查,为春谷谷田除草剂的安全使用提供科学依据。结果表明,苗前使用38%莠去津1 500~2 250 m L/hm2对植株株高影响较小,用量为2 250 m L/hm2时理论产量最高;谷友安全性较好的使用量为1 500 g/hm2;苗后(3~5叶期)38%莠去津安全使用量为1 500~2 250 m L/hm2;2,4-D丁酯的安全使用量为750 m L/hm2;二甲四氯钠安全使用量为1 500 g/hm2。通过对株高影响及理论产量的试验,建议使用的除草剂为播后苗前38%莠去津2 250 m L/hm2,或播后苗前谷友1 500 g/hm2。展开更多
149 complete mitochondrial DNA (mtDNA) cytochrome b (Cyt b) genes (1140 bp) of Gymnocypris przewalskii, Gymnocypris eckloni and Gymnocypris scolisto-mus from the Lake Qinghai, Yellow River and Qaidam Basin were sequen...149 complete mitochondrial DNA (mtDNA) cytochrome b (Cyt b) genes (1140 bp) of Gymnocypris przewalskii, Gymnocypris eckloni and Gymnocypris scolisto-mus from the Lake Qinghai, Yellow River and Qaidam Basin were sequenced and analyzed. Consistent dendrogram indi-cated that the samples collected from the same species do not constitute a separate monophyletic group and all the samples were grouped into three highly divergent lineages (A, B and C). Among them, Lineage A contained all samples of G. przewalskii from the Lake Qinghai and partial samples of the G. eckloni from the Yellow River. Lineage B contained the remaining samples of G. eckloni from the Yellow River. Lineage C was composed of a monophyletic group by G. eck-loni from the Qaidam Basin. Analysis of molecular variance (AMOVA) indicated that most of genetic variations were detected within these three mtDNA lineages (93.12%), sug-gesting that there are three different lineages of Gymnocypris in this region. Our Cyt b sequence data showed that G. przewalskii was not a polytypic species, and G. scolistomus was neither an independent species nor a subspecies of G. eckloni. The divergent mtDNA lineages of G. eckloni from the Yellow River suggested that gene flow between the different populations was restricted to a certain extent by several gorges on the upper reach of the Yellow River. Lineage B of G. eckloni might be the genetic effect from the ancestor which was incorporated with the endemic schizothoracine fishes when the headward erosion of the Yellow River reached to its current headwaters of late. The G. eckloni from Basin Qaidam was a monophyletic group (lineage C) and Fst values within G. eckloni from the Yellow River were higher than 0.98, suggesting that the gene flow has been interrupted for a long time and the G. eckloni from Basin Qaidam might have been evolved into different species by ecology segrega-tion. The correlation between the rakers number of Gymno-cypris and population genetic variation was not significant. All Gymnocypris populations exhibited a low nucleotide di-versity (π = 0.00096―0.00485). Therefore the Gymnocypris populations from Basin Qaidam could have experienced se-vere bottleneck effect in history. Our result suggested Gym-nocypris populations of Basin Qaidam should give a high priority in conservation programs.展开更多
文摘采用随机区组试验,对不同除草剂不同用量处理下的谷子不同生育期株高、穗质量、穗粒质量及理论产量进行取样调查,为春谷谷田除草剂的安全使用提供科学依据。结果表明,苗前使用38%莠去津1 500~2 250 m L/hm2对植株株高影响较小,用量为2 250 m L/hm2时理论产量最高;谷友安全性较好的使用量为1 500 g/hm2;苗后(3~5叶期)38%莠去津安全使用量为1 500~2 250 m L/hm2;2,4-D丁酯的安全使用量为750 m L/hm2;二甲四氯钠安全使用量为1 500 g/hm2。通过对株高影响及理论产量的试验,建议使用的除草剂为播后苗前38%莠去津2 250 m L/hm2,或播后苗前谷友1 500 g/hm2。
文摘149 complete mitochondrial DNA (mtDNA) cytochrome b (Cyt b) genes (1140 bp) of Gymnocypris przewalskii, Gymnocypris eckloni and Gymnocypris scolisto-mus from the Lake Qinghai, Yellow River and Qaidam Basin were sequenced and analyzed. Consistent dendrogram indi-cated that the samples collected from the same species do not constitute a separate monophyletic group and all the samples were grouped into three highly divergent lineages (A, B and C). Among them, Lineage A contained all samples of G. przewalskii from the Lake Qinghai and partial samples of the G. eckloni from the Yellow River. Lineage B contained the remaining samples of G. eckloni from the Yellow River. Lineage C was composed of a monophyletic group by G. eck-loni from the Qaidam Basin. Analysis of molecular variance (AMOVA) indicated that most of genetic variations were detected within these three mtDNA lineages (93.12%), sug-gesting that there are three different lineages of Gymnocypris in this region. Our Cyt b sequence data showed that G. przewalskii was not a polytypic species, and G. scolistomus was neither an independent species nor a subspecies of G. eckloni. The divergent mtDNA lineages of G. eckloni from the Yellow River suggested that gene flow between the different populations was restricted to a certain extent by several gorges on the upper reach of the Yellow River. Lineage B of G. eckloni might be the genetic effect from the ancestor which was incorporated with the endemic schizothoracine fishes when the headward erosion of the Yellow River reached to its current headwaters of late. The G. eckloni from Basin Qaidam was a monophyletic group (lineage C) and Fst values within G. eckloni from the Yellow River were higher than 0.98, suggesting that the gene flow has been interrupted for a long time and the G. eckloni from Basin Qaidam might have been evolved into different species by ecology segrega-tion. The correlation between the rakers number of Gymno-cypris and population genetic variation was not significant. All Gymnocypris populations exhibited a low nucleotide di-versity (π = 0.00096―0.00485). Therefore the Gymnocypris populations from Basin Qaidam could have experienced se-vere bottleneck effect in history. Our result suggested Gym-nocypris populations of Basin Qaidam should give a high priority in conservation programs.
