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51.
52.
西藏地区青稞籽粒营养品质分析及评价 总被引:1,自引:0,他引:1
为探明西藏地区青稞品种间的性状差异及性状间的相关性,筛选优异品质青稞种质,以251个西藏青稞种质资源为材料,测定了籽粒淀粉、粗蛋白、β-葡聚糖、γ-氨基丁酸、大量元素(Ca、P)、微量元素(Fe、Zn、Se)含量共9个品质指标,分析了被测指标间关系。结果表明,所测定的9项品质指标在供试种质资源间均存在不同程度的差异,淀粉含量的变异系数最小,Se含量的变异系数最大;粗蛋白与淀粉含量呈极显著负相关(r= -0.54),粗蛋白与γ-氨基丁酸、Ca、P、Zn、Fe含量均呈极显著正相关。对被测指标进行主成分分析发现,可将9项品质指标简化成3个主成分,其累积方差贡献率为74.5%,其中第一主成分因子的贡献率达到了 48.0%,第一主成分中因子载荷量大的品质指标是Zn、P、Ca、粗蛋白、γ-氨基丁酸、淀粉、Fe含量。综合评价筛选出10个营养品质较高的种质,分别为BJX152、BJX008、BJX149、BJX004、BJX003、BJX015、BJX005、藏青2000、BJX227、喜马拉22号。 相似文献
53.
为了提高绿洲灌区的水资源利用效率,研究了啤酒大麦垄作沟灌栽培的产量效应及节水效果。结果表明,垄作栽培方式有较好的增产、节水、增温效应,与平作栽培相比,4、5月份5cm土层的温度分别提高1.27℃和1.39℃,垄作沟灌栽培啤酒大麦田间长势优于平作栽培,对土壤水分的消耗相对增大,水分对产量的贡献率提高,增产节水效果显著。在相同的灌溉定额下,垄作沟灌较平作栽培啤酒大麦千粒重增加2.10~5.37g,穗粒数增加0.7~7.2粒,产量增加480.5~1 983.6kg.hm-2,增幅6.86%~55.05%,水分利用效率提高5.18%~35.40%,节水1 500m3.hm-2,节水增产效果显著。 相似文献
54.
播期对麦(油)后直播棉产量、品质及氮磷钾利用的影响 总被引:3,自引:0,他引:3
为明确长江流域下游棉区麦(油)后直播棉生产的适宜播期,本研究以?中棉所50‘为材料,于2017—2018年进行大田试验,研究不同播期(5月15日、5月25日、6月4日、6月14日和6月24日)对直播棉产量、品质及养分利用的影响。结果表明,播期推迟,棉花生育进程推迟;花铃期日均温和日照时数降低、有效积温先升高后降低且以6月4日播期花铃期有效积温最高。可见,前3个播期棉花花铃期温光条件较好。棉株与生殖器官的生物量及氮磷钾累积量随播期推迟降低,且前3个播期的棉株生物量和养分累积进入较高速率累积期早于后2个播期的棉株。随着播期的推迟,直播棉成铃数与皮棉产量显著降低。与5月15日播期相比,其余4个播期直播棉的皮棉产量分别降低15.9%~16.9%、13.1%~16.9%、26.9%~33.5%、58.2~62.0%。100kg皮棉氮、磷和钾吸收量随播期推迟而增加,但养分利用效率降低。不同播期间,以6月4日和6月14日播期棉纤维综合品质较优。综上,本试验条件下,5月15日—6月4日是长江流域棉区麦(油)后直播棉获得较高产量的适宜播期,该播期内适当推迟播种有利于棉花优质纤维的形成。 相似文献
55.
本试验用青稞秸秆替代燕麦干草作为唯一粗饲料来源,研究其对生长期藏绵羊体增重及免疫功能的影响。选择18只4~5月龄健康河谷型藏绵羊,随机分为2组,即:青稞组(青稞秸秆300 g/d+精料300 g/d)和燕麦组(燕麦干草300 g/d+精料300 g/d)。试验期4周,第1周为预试期,第2~4周为正试期。正试期结束后,按公母各占1/2原则,各组分别选取6只羊屠宰采样。结果发现:青稞组与燕麦组藏绵羊的体重、日增重、脾脏重和脾脏指数均差异不显著(P0.05);青稞组与燕麦组藏绵羊血清中免疫球蛋白(Ig)G、Ig A、Ig M、溶菌酶含量和酸性磷酸酶活性均差异不显著(P0.05),但青稞组中溶菌酶含量有高于燕麦组的趋势(P=0.083);青稞组与燕麦组血清、胸腺和脾脏白细胞介素(IL)-2、IL-4、IL-6、IL-10和干扰素γ(IFN-γ)含量均差异不显著(P0.05)。综合来看,与燕麦干草相比,饲喂青稞秸秆不会降低生长期藏绵羊的体增重及免疫性能,且有提高机体非特异性免疫因子(溶菌酶)含量的潜力,可作为藏绵羊的粗饲料来源。 相似文献
56.
57.
K. Madriz-Ordeñana R. Rojas-Montero T. Lundsgaard P. Ramírez H. Thordal-Christensen & D.B. Collinge 《Plant pathology》2000,49(2):302-307
Maize rayado fino marafivirus (MRFV) was mechanically transmitted to kernels of three Costa Rican maize cultivars by the vascular puncture technique. A transmission rate of up to 43.2% was obtained for cultivar HC-57. The rate of MRFV transmission to maize was possibly affected by the morphology of the kernel, which may influence physical access to the vascular tissue after water imbibition. Transmission to maize was confirmed by western blot and immunosorbent electron microscopy. By slight modifications of the procedure, MRFV was also transmitted to barley. This is the first report of MRFV infecting a species outside the supertribe Andropogonodae. Virus infection and replication in barley were confirmed by RT-PCR detection of MRFV RNA and by detection of the virus by ELISA. 相似文献
58.
Bo J. M. Secher Lise N. Jrgensen N. S. Murali Peter S. Boll 《Pest management science》1995,45(2):195-199
The decision in 1986, on an action plan to reduce pesticide use in Denmark by 50% led to increased research on the potential of reducing dosages. A decision support system (PC-Plant Protection), developed by The Danish Institute for Plant and Soil Science, implements this research. It combines a detailed use of threshold values to support decisions on treatment need, choice of pesticides and the appropriate dosage for actual problems in cereals. The pest and disease module within the system has been available commercially since 1993 and up to the end of April 1995, 2000 licences have been issued for its use at agricultural schools and by advisers and farmers. The recommendation model for pest and disease control has been validated in field trials since 1990. The validation has shown that the model is able to provide recommendations for the control of pests and diseases to a satisfactory level, without affecting farmers' gross margins. The model was able to adjust pesticide use to large yearly variations and the average amount of pesticides in the plots treated according to the model was well below that in the reference plots and in the commonly used strategies in Denmark. 相似文献
59.
Nickolas?G.?KavallieratosEmail author George?J.?Stathas Christos?G.?Athanassiou George?Th.?Papadoulis 《Phytoparasitica》2002,30(3):231-242
The role of the self-sown shrubsDittrichia viscosa (L.) W. Greuter andRubus ulmifolius Schott as reservoirs of aphid parasitoids was investigated. In the field studies conducted,D. viscosa grew adjacent to crops of durum wheat and barley andR. ulmifolius grew adjacent to cotton. The relative abundance of the parasitoids of(a) Capitophorus inulae (Passerini) onD. viscosa, (b) Rhopalosiphum padi (Linnaeus) on durum wheat and barley,(c) Aphis ruborum (Börner) onR. ulmifolius, and(d) Aphis gossypii Glover on cotton in various parts of Greece, was assessed during the years 1996–2000. In 2000, the fluctuation of parasitization of the above four aphid species was recorded and the action of the aphidophagous predators of the family Coccinellidae was studied. It was observed thatAphidius matricariae Haliday predominated onC. inulae andR. padi in all sampling cases. In contrast,Lysiphlebus fabarum (Marshall) was the dominant species parasitizingA. ruborum onR. ulmifolius andA. gossypii on cotton in Thessaly (central Greece) and Macedonia (northern Greece), whereasLysiphlebus confusus Tremblay et Eady andBinodoxys acalephae (Marshall) were the dominant parasitoid species in Thrace (northern Greece).Coccinella septempunctata Linnaeus was the most abundant coccinellid species on durum wheat, whereasAdonia variegata (Goeze) predominated on cotton. However, coccinellid individuals were scarce on bothD. viscosa andR. ulmifolius. The present study indicated that these two shrubs can be regarded as useful reservoirs of aphid parasitoids. 相似文献
60.
We investigated the tolerance to weed harrowing of four spring barley varieties and examined the possible interactions between varietal weed suppressive ability and two nutrient levels. Tolerance was defined as the combined effect of crop resistance (ability to resist soil covering) and crop recovery (the ability to recover in terms of yield). The weed harrowing strategy was a combination of one pre‐ and one post‐emergence weed harrowing. In terms of yield, the four varieties responded significantly differently to weed harrowing and the response depended on nutrient level. At the lower nutrient level, weed harrowing caused an increase in yield of 4.4 hkg ha−1 for a strong competitor (cv. Otira), while there was no effect on yield at the higher nutrient level. For a weaker competitor (cv. Brazil), weed harrowing caused no change in yield at the lower nutrient level, whereas yield decreased by 6.0 hkg ha−1 at the higher nutrient level. There were marked differences between the weed suppressive ability of the four varieties when not harrowed, with less pronounced but significant differences when harrowed. Weed harrowing did not change the weed suppressive ability of a variety. Varieties that are tall at post‐emergence harrowing and have increased density after pre‐emergence harrowing, are the ones that benefit most from weed harrowing. 相似文献