Effect of Main Cultivation Factors on Quality Combination Parameters of High-quality Brassica napus Hybrids

[Objective] This study aimed to analyze the influence of five cultivation factors including sowing date, plant density, nitrogen fertilizer amount, phosphate fertilizer amount and potash fertilizer amount on the quality parameters of Brassica napus hybrid＆ [Method] Statistical analysis on the data from previous studies and our work was carried out [Result] The contents of erucic acid, thioglycoside, oil, oleic acid and linoleic acid were negatively correlated with the sowing date, while the contents of seed protein, palmitic acid, stearic acid and linolenic acid were positively correlated with the sowing date. The total amount of fat and protein, the ratio of unsaturated fatty acid （UFA） to saturated fatty acid （SFA）, the fatty acid （FA） of erucic acid chain, the total amount of oleic acid and linoleic acid were negatively correlated with the sowing date; the UFA content, the unsatu- ration index, the SFA content, the 18-C FA content, and the ratio of UFA to FA in erucic acid chain were positively correlated with the sowing date. The contents of erucic acid, thioglycoside, seed protein, oleic acid, linolenic acid and eicosenoic acid were negatively correlated with the plant density, while the contents of oil, palmitic acid, stearic acid and linoleic acid were positively correlated with the plant density. The total amount of fat and protein （F ＆ P）, and the ratio of UFA to FA in erucic acid chain were negatively correlated with the plant density, while the UFA content, the unsaturation index, the SFA content, the ratio of UFA to SFA, the 18-C FA content, the FA in erucic acid chain, and the total amount of oleic acid and linoleic acid were positively correlated with the plant density. The contents of erucic acid, thioglycoside, oil, protein in milled rapeseed, palmitic acid and eicosenoic acid were negatively correlated with the nitrogen fertilizer amount, while the contents of seed protein, oleic acid, stearic acid, linoleic acid and linolenic acid were posi- tively correlated with the nitrogen fertilizer amount; the total F ＆ P, the unsaturation index and the ratio of UFA to FA in erucic acid chain were positively correlated with the nitrogen fertilizer amount, while the UFA content, the SFA content, the FA in erucic acid chain, the total amount of oleic acid and linoleic acid, the ratio of UFA to SFA, and the 18-C FA content were negatively correlated with the nitrogen fertilizer amount The contents of erucic acid, thioglycoside, seed protein, linoleic acid and linolenic acid were negatively correlated with the potash fertilizer amount, while contents of oil, oleic acid, stearic acid and eicosenoic acid were positively correlated with the potash fertilizer amount; the total F ＆ P, the unsaturation index, the SFA, and the ratio of UFA to FA in erucic acid chain were negatively correlated with the potash fertilizer amount There were negative correlations between the contents of erucic acid, thioglycoside, seed protein, palmitic acid, stearic acid, linoleic acid, linolenic acid and phosphate fertilizer amount; positive correlations between the contents of oil, oleic acid, eicosenoic acid and phosphate fertilizer amount The total UFA, the unsaturation index, the 1843 FA, the SFA, the FA in erucic acid chain, and the ratio of UFA to FA in erucic acid chain were negatively correlated with the phosphate fertilizer amount [Conclusion] This study identified the correlations of the five cultivation factors with the quality parameters of high-quality Brassica napus hybrids, to provide theoretical basis for its cultivation.

Control Effects of Bacillus subtilis DJ-6 and Pyraclostrobin Alone and in Combination Against Fusarium oxysporum

[Objective] This study was conducted to screen a synergistic biological fungicide complex to control Fusarium wilt, reducing the use of chemical pesticides. [Method] The inhibitory effects of Bacil us subtilis DJ-6 and pyraclostrobin alone or in combination at five ratios against Fusarium oxysporum were detected by mea-suring mycelium growth rate in laboratory tests. The growth promotion and disease control effect of combined or single use of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 WP at 1∶1 000, 1∶2 000 and 1∶3 000 dilutions were detected in field trials. [Result] The EC50 values of combined use of B. subtilis DJ-6 and pyra-clostrobin at ratios of 1∶1, 1∶2, 1∶3, 1∶4 and 1∶5 against F. oxysporum were 5.311 5, 4.008 6, 3.570 6, 3.350 9 and 3.218 9 μg/ml, with the synergistic ratios （SR） of 2.28, 1.77, 1.53, 1.64, 1.11, among which the synergetic effect at 1∶1 was the best. The fungicidal activity of pyraclostrobin was greater than that of B. subtilis DJ-6 in laboratory tests. Field trials revealed that al the 1∶1 000, 1∶2 000 and 1∶3 000 dilu-tions of 20% pyraclostrobin·2×1011 cfu/g B. subtilis DJ-6 WP in combination, 1∶1 000 dilution of 1 ×1012 cfu/g B. subtilis DJ-6 WP and 1∶2 000 dilution of 250 g/L pyra-clostrobin EC promoted the growth of strawberry by increasing plant height, leaf petiole, leaf blade area and stem diameter. Among them, the treatments with 1∶1 000 and 1∶2 000 of 20% pyraclostrobin · 2×1011 cfu/g B. subtilis DJ-6 WP in combina-tion had better effects than other treatments. The control effects of al the treat-ments were measured 30 and 80 d after fungicide application. The control effects of 1∶1 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combina-tion were up to 100% and 93.11%, which were higher than those in al other treat-ments. The second highest control effects were found in the treatment with 1∶ 2 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combination, they were 92.49% and 86.49%, higher than those in other treatments except the 1∶1 000 dilution of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 in combination. The control effects of 1∶3 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combination were 82.61% and 72.42%, higher than those in treatment with 1∶1 000 dilution of 1×1012 cfu/g B. subtilis DJ-6 WP, but lower than those in treat-ment with 1∶2 000 dilution of 25% pyraclostrobin EC. [Conclusion] Al the results re-vealed that the combination use of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 WP at 1∶1 000 to 1∶2 000 dilution had better control effect against strawberry Fusarium wilt.

Pollinator-dependent evolution of floral trait combinations in an orchid herb

Aims As one of the most important agents driving floral evolution,pollinators shape the diversity of flowers in angiosperms.However,most previous studies have only quantified pollinators driving the evolution of a single floral trait,and experimental estimates of the potential role of pollinators in shaping the evolution of floral trait associations are relatively rare.Methods We experimentally identified and estimated the pollinator-mediated directional and correlational selection on single floral traits and trait combinations across 2 years in an orchid species,Spiranthes sinensis.Important Findings Pollinators mediated directional selection for an earlier flowering start date and larger corolla size.Pollinators mediated positive correlational selection on the combinations of floral display traits and negative correlational selection on the combinations of flowering phenology and floral display traits.In addition,the strength of selection differed over time.Our results highlight the potential role of pollinators in driving the evolution of floral trait combinations and suggest that it is necessary to consider floral character functional associations when seeking to understand and predict the evolutionary trajectory of flowers in angiosperms.