大口黑鲈饲料中2种植物性蛋白质混合物替代鱼粉的研究

为了探讨在大口黑鲈饲料中去皮豆粕分别与玉米蛋白和大米蛋白组成的2种植物性蛋白质混合物替代鱼粉的可行性,分别于含45%和30%鱼粉的配方中配比上述2种植物性蛋白质混合物,配制成4种等氮等能的饲料。用上述饲料饲养初始体质量为(58.69±0.07)g的大口黑鲈53 d。结果显示:30%鱼粉组的终末体质量和特定生长率显著高于45%鱼粉组(P0.05),而饲料效率、蛋白质效率、蛋白质消化率和氨基酸消化率之间无显著性差异(P0.05)。玉米蛋白组的饲料效率和蛋白质效率显著高于大米蛋白组(P0.05),而摄食量显著低于大米蛋白组(P0.05)。全鱼和肌肉的粗蛋白质、粗脂肪、水分和灰分各组间差异不显著(P0.05)。30%鱼粉组的血清溶菌酶活性和血清蛋白含量显著高于45%鱼粉组(P0.05),而玉米蛋白组和大米蛋白组对血清溶菌酶活性和血清蛋白含量的影响差异不显著(P0.05)。红细胞数和红细胞压积各组间差异不显著(P0.05)。本研究表明,去皮豆粕分别与玉米蛋白和大米蛋白组成的植物性蛋白质混合物可以使大口黑鲈饲料中的鱼粉含量由45%降至30%;去皮豆粕与玉米蛋白组成的植物性蛋白质混合物的替代效果优于去皮豆粕与大米蛋白组成的植物性蛋白质混合物。     

Yield stability studies of soybean (Glycine max (L.) Merrill) under rhizobia inoculation in the savanna region of Nigeria

Soybean (Glycine max (L.) Merrill) production is expanding into temperate and tropical environments. Yield stability studies under rhizobia inoculation were investigated in 24 soybean genotypes over two successive growing seasons at three agro‐ecological zone of Nigeria, during the 2015–2016 rainy seasons. Treatments were arranged in a split‐plot design and replicated three times. Treatments were 24 soybean genotypes and three levels of rhizobia inoculation. Results indicated that the variation of genotypes and inoculation on percentage emergence, height, number of leaves, number of branches per plant, total biomass yield, above‐ground biomass and seed yield was significant (p = .05). The effects of genotypes (G), environment (E) and G × E interactions on seed yield were also significant. Two soybean genotypes (TGx 1989‐45F and TGx 1990‐110FN) were identified as the most promising in relation to yield stability. Of the three locations, Abuja produced the least interaction effects followed by Igabi and may be most appropriate environments for large‐scale soybean production. Appropriate inoculation of soybean with inoculants (LegumeFix and or NoduMax) should be encouraged in farmer's field.     

大豆秸秆生物炭对铅锌尾矿污染土壤的修复作用

采用盆栽空心菜的方法,研究了大豆桔杆生物炭对铅锌尾矿污染土壤的修复作用。污染土壤中Cu、Zn、Pb和Cd含量分别为50,400,1 119,3.4mg/kg。结果表明:土壤无论是否受到铅锌尾矿污染,添加3%生物炭(w/w)均能显著提高土壤pH;3%生物炭能够抑制铅锌尾矿污染导致的土壤pH降低。大豆桔杆生物炭对尾矿污染土壤和未污染土壤中重金属有效态的影响不同,与未污染土壤相比,3%生物炭的钝化作用不能抵消铅锌尾矿污染导致的重金属有效态含量的增加。铅锌尾矿污染抑制空心菜生长;施加3%生物炭可以消除铅锌尾矿污染对空心菜生长的抑制作用。生物炭显著降低污染土壤空心菜根部重金属含量,而对地上部分的影响,不同元素表现出不同的特点;3%生物炭能够阻控铅锌尾矿污染土壤中Cu、Zn、Pb和Cd向空心菜地上部迁移富集。大豆桔杆生物炭对空心菜吸收重金属的影响,在铅锌尾矿污染土壤和未污染土壤上表现不同,存在元素之间的拮抗作用以及由于生物炭提高空心菜生物量所产生的稀释作用。在研究设置条件下,与未污染土壤相比,从空心菜生物量和可食部分吸收重金属含量来评价,施加3%大豆桔杆生物炭可以修复铅锌尾矿导致的土壤污染。     

Nectar secretion of RN-type cytoplasmic male sterility three lines in soybean [Glycine max (L.) Merr.]

Significant progress has been achieved in the use of heterosis in soybean and several soybean hybrids have been released in China. However, broad use of hybrid soybean seed is limited due to low seed setting of female parents. Breeding cytoplasmic male sterile(CMS) lines with high out-crossing rate is necessary to solve the problem. The objective of this study was to determine the relationship between out-crossing rate of CMS lines and their nectar secretion. The daily nectar secretion rhythm, meteorological effect on nectar secretion, and differences in nectar secretion among genotypes and years were investigated in 27 soybean CMS lines(A-lines) with their maintainers(B-lines) and restorers(R-lines). The correlation between out-crossing rate of CMS lines and nectar production was also evaluated. Nectar secretion had diurnal variation. Secretion initiated at about 06:00 for most materials and reached a peak at 07:00–08:30 after flower opened, then the nectar secretion decreased gradually. A sub-peak appeared at about 13:00, while the nectar could not be detected at 17:00. Nectar secretion was greatly influenced by the weather conditions. The amount of nectar secretion increased gradually over time during periods of high temperature and no rainfall for several days. Rainy weather and low temperatures inhibited nectar secretion. There were obvious variations of nectar amount among different genotypes tested. Significant nectar variation within a genotype among years was also observed, and the highest nectar secretion was 3-fold higher than the lowest. The amount of nectar secretion from R-lines was significantly higher than that of A-and B-lines. There was no significant difference in nectar secretion between A-and B-lines. A-and B-lines with higher out-crossing rates secreted more nectar. The amount of nectar secretion of A-and B-lines were significantly positively correlated with the out-crossing rate of A-lines.     

Chemical mutagenesis and soybean mutants potential for identification of novel genes conferring resistance to soybean cyst nematode

The resistance of soybean (Glycine max (L.) Merr.) to soybean cyst nematode (SCN, Heterodera glycines Ichinohe), which is a devastating pathogen in soybean production and causes a large quantity of annual yield loss worldwide, can shift during the long-term interaction and domestication. It is vital to identify more new resistance genetic sources for identification of novel genes underlying resistance to SCN for management of this pathogen. In the present study, first, two ethane methylsulfonate-mutagenesis soybean M2 populations of PI 437654, which shows a broad resistance to almost all of SCN races, and Zhonghuang 13, which is a soybean cultivar in China conferring strong resistance to lodging, were developed. Many types of morphological phenotypes such as four- and five-leaflet leaves were observed from these two soybean M2 populations. Second, 13 mutants were identified and confirmed to exhibit alteration of resistance to SCN race 4 through the forward genetic screening of 400 mutants of the PI 437654 M2 population, the rate of mutants with alteration of SCN-infection phenotype is 3.25%. Third, these identified mutants were further verified not to show any changes in the genomic sequences of the three known SCN-resistant genes, GmSHMT08, GmSNAP18 and GmSANP11, compared to the wild-type soybean; and all of them were still resistant to SCN race 3 similar to the wild-type soybean. Taken together, we can conclude that the 13 mutants identified in the present study carry the mutations of the new gene(s) which contribute(s) to the resistance to SCN race 4 in PI 437654 and can be potentially used as the genetic soybean sources to further identify the novel SCN-resistant gene(s).     

Suitability of the DNDC model to simulate yield production and nitrogen uptake for maize and soybean intercropping in the North China Plain

Intercropping is an important agronomic practice. However, assessment of intercropping systems using field experiments is often limited by time and cost. In this study, the suitability of using the DeNitrification DeComposition(DNDC) model to simulate intercropping of maize(Zea mays L.) and soybean(Glycine max L.) and its aftereffect on the succeeding wheat(Triticum aestivum L.) crop was tested in the North China Plain. First, the model was calibrated and corroborated to simulate crop yield and nitrogen(N) uptake based on a field experiment with a typical double cropping system. With a wheat crop in winter, the experiment included five treatments in summer: maize monoculture, soybean monoculture, intercropping of maize and soybean with no N topdressing to maize(N0), intercropping of maize and soybean with 75 kg N ha~(–1) topdressing to maize(N75), and intercropping of maize and soybean with 180 kg N ha~(–1) topdressing to maize(N180). All treatments had 45 kg N ha~(–1) as basal fertilizer. After calibration and corroboration, DNDC was used to simulate long-term(1955 to 2012) treatment effects on yield. Results showed that DNDC could stringently capture the yield and N uptake of the intercropping system under all N management scenarios, though it tended to underestimate wheat yield and N uptake under N0 and N75. Long-term simulation results showed that N75 led to the highest maize and soybean yields per unit planting area among all treatments, increasing maize yield by 59% and soybean yield by 24%, resulting in a land utilization rate 42% higher than monoculture. The results suggest a high potential to promote soybean production by intercropping soybean with maize in the North China Plain, which will help to meet the large national demand for soybean.     

大豆农家品种资源芽期耐盐性鉴定及耐盐品种筛选

栽培大豆属于中度耐盐植物,盐胁迫导致其正常的生长发育进程受到抑制。本研究测定了NaCl处理下,18份大豆农家品种资源的发芽率、发芽势、株高、胚轴长、根长、侧根数、干物质积累等指标。明确了NaCl胁迫条件下,发芽率、发芽势、株高、胚轴长、根长、侧根数、干物质积累等指标均呈降低趋势。筛选出耐盐品种G08,盐害指数18.00%。证明了发芽势、发芽率、株高、胚轴长、根长与品种间耐盐性呈显著相关关系,能更好的反应大豆的耐盐性。为大豆耐盐种质创制提供丰富的数据参考和亲本材料,为完善大豆种质资源耐盐性研究和提高盐渍土壤利用效率提供资料依据。     

红边与短波红外谱段玉米大豆识别能力研究

[目的]研究旨在挖掘红边、短波红外谱段对玉米大豆识别精度的提升程度,发现分辨率和谱段对作物识别的综合影响规律。[方法]采用德国Rapideye和美国Landsat-OLI数据,基于最大似然监督分类的方法,针对玉米、大豆、其他等3种地物类型。[结果]结果表明,与仅有蓝、绿、红、近红外波段相比,增加红边后总体分类精度从73.1%提高到80.5%。与仅有气溶胶、蓝、绿、红、近红波段相比,增加1个短波红外波段后,总体分类精度从72.9%提高到75.4%。[结论]中分辨率多时相数据能够弥补由于缺少短波红外、降低空间分辨率造成的识别精度的下降。     

紫云英施用量对土壤活性有机碳和碳转化酶活性的影响

利用紫云英还田的定位试验研究不同紫云英施用量下土壤活性有机碳含量和碳转化酶活性的变化。试验包括对照、施用化肥和4个紫云英施用量(30、60、90和120 t·hm~(-2))处理。结果表明:与对照相比,施用化肥和紫云英均能够显著增加土壤活性有机碳(可溶性有机碳、热水提取态有机碳、微生物生物量碳和颗粒有机碳)含量,并且随着紫云英施用量的增加土壤活性有机碳含量显著增加。土壤碳转化酶活性的变化规律与土壤活性有机碳相同,其中施用化肥和紫云英较对照处理分别提高14%和24%~55%的纤维素酶活性、27%和45%~187%的蔗糖酶活性、42%和51%~165%的β-葡萄糖苷酶活性、11%和11%~24%的酚氧化酶活性以及16%和16%~27%的过氧化物酶活性。与对照相比,施用化肥对相对酶活性(酶活性与微生物生物量碳的比值)无显著影响;增加紫云英施用量能够显著增加相对蔗糖酶和相对β-葡萄糖苷酶活性,降低相对酚氧化酶活性和相对过氧化物酶活性。逐步回归分析表明土壤活性有机碳组分含量主要受纤维素酶、β-葡萄糖苷酶和酚氧化酶活性的影响。     

Soy protein concentrate as a substitute for fish meal in diets for juvenile Acanthopagrus schlegelii: effects on growth,phosphorus discharge and digestive enzyme activity

The current high demand and cost of fish meal (FM) necessities the evaluation of alternative plant protein ingredients in diets of farmed marine fish. A 56‐day feeding trial was performed to study the effects of replacement of FM with soy protein concentrate (SPC) in diets of Acanthopagrus schlegelii. Diets were prepared at levels of 0%, 30%, 47.5%, 65%, 82.5% and 100% SPC, respectively, replacing FM. The results indicated no significant differences (p > .05) in % weight gain (WG) and specific growth rate of fish fed S30% to S82.5% diets compared with the control diet while, further inclusion at 100% significantly depressed growth performance. SPC inclusion and phytase supplementation significantly affected the phosphorous discharge (P‐load) showing lowest value (3.83 ± 0.53 g/kg WG) in S100% compared to control (14.79 ± 0.37 g/kg WG) and in fish fed S30% diet (13.24 ± 0.89 g/kg WG) (p < .05). The results of this study showed that FM could be substituted up to 82.5% by SPC in the diet of Acanthopagrus schlegelii fingerlings (5.53 ± 0.12 g) without any adverse effects. Phytase supplementation SPC based diets could be effective in reducing the phosphorus load in the aquatic culture environment.