不同来源知母种子的质量比较

[目的]通过对知母种子的质量进行检测分析,比较不同来源知母种子的质量优劣.[方法]采用常规检验方法分别测定知母种子的净度、千粒重、发芽率、发芽势和生活力等指标.[结果]7种不同来源的知母种子质量上存在较大差异.[结论]陵川、襄汾、易县、亳州的知母种子质量较好,可作为知母生产引种繁殖的优选种质材料.     

秸秆还田方式对土壤理化性质的综合影响评价

为了探究适合于砂姜黑土地区麦玉轮作模式下的秸秆还田方式,在增加养分的同时减少养分流失风险.设置7种秸秆还田处理方式:A(小麦秸秆全还田,玉米秸秆不还田)、B(玉米秸秆全还田,小麦秸秆不还田)、C(小麦玉米秸秆全还田)、D(施肥但秸秆不还田CK1)、E(小麦秸秆半还田,玉米秸秆不还田)、F(玉米秸秆半还田,小麦秸秆不还田)和G(秸秆不还田也不施肥CK2).对不同处理土壤进行理化分析,同时运用熵权法对土壤进行质量评价,以及对土壤中有潜在流失风险的养分进行评估.结果 表明:与不还田也不施肥的对照相比,在0～20 cm土层中,除C处理外均可提升土壤含水率,分别提升了66.9％、50.1％、31.1％、51.2％和77.2％;不同处理土壤中微生物量氮、全氮、硝氮和总磷含量依次是:G＜D＜E＜F＜B＜A＜C,土壤中有机碳含量与秸秆还田量有关,含量大小依次是G＜D＜E＜F＜A＜B＜C.养分评价得分中,养分增加效果C＞B＞A＞F＞E＞D＞G,各秸秆还田处理养分流失风险依次是E＞F＞C＞A＞B.综合考虑养分增加与流失风险,在各处理中小麦玉米秸秆全量还田处理C是一种能够在增加养分的基础上降低潜在面源污染风险的还田方式.     

不同植物生长调节剂对金橘果实生长及产量的影响

[目的]筛选出金橘保果壮果的理想植物生长调节剂,以促进金橘产业的健康快速发展.[方法]于金橘谢花7 d后喷施30 mL/L赤霉素(GA3),间隔7和14d后再分别喷施一次30 mL/L GA3+10 mL/L萘乙酸(NAA)(处理1)、5mL/LCTK+10 mL/L NAA(处理2)、1mL/L噻苯隆(处理3),以喷清水为对照,观察测定各处理的坐果率、果实生长发育规律、产量及单果重.[结果]以处理1和处理3的金橘坐果率较高,均在20.00％以上,比对照提高了49.96％和46.68％.处理2和处理3的果实生长发育较快,其果实横径比对照增加了3.12和2.80 mm,纵径比对照增加了3.66和1.97 mm.在单果重与产量方面,也是以处理2、处理3的效果较显著,单株产量较对照提高了13.5％和11.6％,单果重比对照增加了34.0％和26.9％.[结论]在金橘谢花后7d喷施一次30 mL/L GA3,间隔7和14 d后再分别喷施一次5 mL/L CTK+10mL/L NAA,可有效提高果实产量和经济效益,建议生产上大力推广应用.     

花粉直感效应对桂单0810百粒重的影响

【目的】研究不同玉米品种花粉对桂单0810百粒重的影响,为挖掘该品种的产量潜力奠定基础。【方法】采用完全随机区组设计,利用8个不同玉米杂交种作为父本,对桂单0810进行人工授粉,并对不同杂交种分别进行自交及姊妹交。果穗成熟后,测定自交、姊妹交及杂交果穗的籽粒百粒重。【结果】同一品种自交果穗与姊妹交果穗的百粒重间表现出不同程度的差异,亚航639和太平洋98自交果穗籽粒百粒重比姊妹交极显著降低5.47%和5.36%（P＜0.01,下同）;琛玉969、桂单0810和迪卡008自交百粒重比姊妹交增加0.35%~2.64%,其他各品种自交百粒重比姊妹交降低0.19%~2.11%,且均未达显著水平（P＞0.05,下同）。8个玉米品种的花粉均可增加桂单0810的百粒重,其中正大808、太平洋98、先达901、琛玉969和亚航639等5个品种花粉可极显著增加桂单0810的百粒重。8个玉米品种与桂单0810的杂交组合百粒重均表现出当代（F0）杂种优势（1.31%~12.70%）,7个杂交组合表现出超亲优势。杂种优势最明显的是桂单0810×正大808组合,百粒重比母本桂单0810和父本正大808分别提高12.70%和15.68%,中亲优势达14.17%。【结论】玉米品种桂单0810易接受外来玉米品种花粉,通过花粉直感效应增加自身百粒重并具有当代杂种优势和超亲优势;其花粉直感效应因父本基因型不同而异。     

NUTRIENT UPTAKE AND USE EFFICIENCY BY TROPICAL LEGUME COVER CROPS AT VARYING PH OF AN OXISOL

Oxisols comprise large soil group in tropical America. These soils are acidic and have low fertility. Use of tropical legume cover crops in cropping systems is an important strategy to improve fertility of these soils for sustainable crop production. Data are limited on nutrient uptake and use efficiency of tropical cover crops under different acidity levels. The objective of our study was to evaluate growth and nutrient uptake parameters of sixteen tropical legume cover crops under three soil pH (5.1, 6.5, and 7.0) of an Oxisol. Shoot dry weight was influenced significantly by pH and cover crop treatments and their interactions, indicating that cover crops used had differential responses to changing soil pH levels. Overall, shoot dry weight decreased when soil pH was raised from 5.1 to 7.0, indicating acidity tolerance of cover crops. Nutrient concentration (content per unit of dry weight), uptake (concentration X dry weight), and nutrient use efficiency (dry weight of shoot per unit of nutrient uptake) varied significantly among cover crops. The variation in nutrient uptake and use efficiency among cover crop species was associated with variation in shoot dry matter production. Significant variation among crop species in dry matter production and low C/N ratios (average value of 14.25) suggest that cover crops which produced higher dry matter yield like white jack bean, gray mucuna bean, black mucuna bean, mucuna bean ana, and lablab are important choices for planting in tropical soils to recover large amount of macro and micronutrients, and to prevent such nutrient leaching in soil plant systems.     

一种基于模糊的修复后土壤环境风险综合评价方法

Environmental risks pertaining to contaminated soils have been well studied, while little attention has been paid to the risks of the soils after remediation. In this study, a concept model developed based on fuzzy set theory was applied to evaluate the uncertainties of three risk indicators, namely, plant growth, groundwater safety and human health, of a restored site that had been previously polluted by heavy metals. The concept model classified the grade and importance of risk factors by an 11-level ranking system and was able to yield a comprehensive risk result rather than multi-risk results for complex risk indicators. Modeling results showed that the risks to the three indicators were effectively reduced after the remediation. Moreover, great sensitivity of the risks was found related to the weight distribution among the three risk indicators. In general, the risks of both polluted and restored soils to the environment were in the order of groundwater safety 〉 plant growth 〉 human health. The model was proved to solve the problems of multi-risk results due to complex risk indicators that previously encountered by other researchers, which made it helpful in decision-making and management of restored soils.     

Diversity and association analysis of important agricultural trait based on miniature inverted-repeat transposable element specific marker in Brassica napus L.

Miniature inverted-repeat transposable elements(MITEs)are a group of DNA transposable element(TE)which preferentially distributed with gene associated regions.Tens of MITEs families have been revealed in Brassica napus genome,they scatter across the genome with tens of thousands copies and produce polymorphisms both intra-and inter-species.Our previous studies revealed a Tourist-like MITE,Monkey King,associated with vernalization requirement of B.napus,however there are still few studies reveal MITE association with agricultural traits in B.napus.In the present study,80 polymorphic markers were developed from 55 MITEs,and used to evaluate genetic diversity in a panel of B.napus accessions consisting of 101 natural and 25 synthetic genotypes.Five agricultural traits,oil content,glucosinolate content,erucic acid content,weight of thousand seeds(WTS)and plant height,were investigated across 3-years field experiments,in addition,two traits,hypocotyl length and root length,were evaluated at the 4-leaf stage in the laboratory.Correlations between the MITE-based markers and seven traits were analyzed,finally,10 polymorphic markers produced by 6 pairs of MITE specific primers were revealed relatively high correlation with 5 traits.Two polymorphic markers were anchored with two candidate genes,BnaA02g13530D and BnaA08g20010D,respectively,which may contribute to glucosinolate content and WTS.This research may contribute to genetic improvement through utilization of MITE-induced polymorphisms in Brassica species.     

不同营养水平全混合日粮（TMR）饲喂利杂牛育肥效果分析

[方法]研究采用全混合日粮（TMR）饲喂方式,对利木赞牛与本地黄牛杂交改良后代F1进行低、中、高3个不同营养水平（15～18月龄,分别编为试验Ⅰ组、Ⅱ组、Ⅲ组）的日粮配方筛选试验,基础日粮为全株玉米青贮+玉米芯+苜蓿干草+肉牛精料补充料,试验期100 d。[结果]研究结果表明,从平均期末体重、期内总增重及日增重指标来看,试验Ⅲ组（高营养水平）平均日增重达（1.63±0.33） ㎏,高于Ⅰ组（1.58±0.29） kg和Ⅱ组（1.61±0.30） kg,按平均期末体重、期内总增重和日增重排序,为试验Ⅲ组（高营养水平）>Ⅱ组（中营养水平）＞Ⅰ组（低营养水平）,试验结果的趋势表明,同品种组合杂种肉牛不同营养水平,其育肥增重效果不同。但组间差异不显著（P＞0.05）,可能与标本量不足有关。在经济效益方面,随着精补料/增重比重的增加,相应试验组肉牛的产出增加,但同时也增加了养殖成本,从试验组的头均纯收益、新增投入占产出比以及总投入占产出比3个方面进行从低到高的排序为Ⅲ组（高营养水平）＜Ⅱ组（中营养水平）＜Ⅰ组（低营养水平）。[结论]试验结果表明,此结果与其平均日增重和日料的营养水平是相吻合的。因此,为了节本增效,应充分利用宁夏地区的优势杂交肉牛组合,同时辅以标准化的、能够充分利用当地饲草优势的、多元化的、科学的日粮配方。     

犊牛早期(3月龄)断奶生长发育情况分析

[目的]探索犊牛早期(3月龄)断奶的可行性,为推广犊牛早期(3月龄)断奶技术提供依据,增加养殖企业的经济效益成本。[方法]试验选取出生后3月龄的西门塔尔犊牛,进行断奶饲养,测量断奶后不同日龄的体重及体尺指标,分析其生长发育情况,并对体重及体尺进行相关性分析。[结果]西门塔尔犊牛断奶后增重快速,断奶后90天,犊牛平均体重达到269.67kg,断奶后平均总增重达到101.54kg,全程日均增重为1128.22g。断奶后90天与断奶后30天比较,体斜长、体高、胸宽、胸深、胸围、腹围、臀围均呈现增加的趋势,其中增长较快的是腹围,其次是胸围,分别增加了19.0cm,14.67cm。体重与体斜长、体高、胸宽、胸深、胸围、腹围、臀围均呈正相关,其中体重与体斜长、体高、胸深、胸围、腹围呈极显著相关(p<0.01)。[结论]犊牛早期(3月龄)断奶后犊牛生长发育情况较好,犊牛早期(3月龄)断奶具有较强的可行性,可大范围推广。     

Feeding Acacia etbaica and Dichrostachys cinerea fruits to smallholder goats in northern Ethiopia improves their performance during the dry season

Acacia etbaica Schweinf. and Dichrostachys cinerea (L.) Wight et Arn. are among the common woody browse plants that naturally grow in many arid and semi-arid rangelands in sub Saharan Africa. An experiment was conducted to compare the voluntary dry matter intake, body weight gain, nitrogen balance, carcass composition and sensory attributes of goats supplemented with different levels of A. etbaica and D. cinerea fruits. Average initial body weight of the goats was 20.4 kg (± 0.8SE) and received one of the following fruit supplementation regimes for 120 days (on body weight basis, n = 4 goats per group): (1) Control, no supplement; (2) 0.5% of A. etbaica; (3) 0.5% of D. cinerea; (4) 1.0% of A. etbaica; (5) 1.0% of D. cinerea; (6) 1.5% of A. etbaica; (7) 1.5% of D. cinerea. All groups were allowed to graze/browse during the day. Compared to A. etbaica, D. cinerea fruits contained higher amounts of crude protein (182 vs 135 g/kg DM), metabolizable energy (11 vs 8.4 MJ/kg DM), and in vitro dry matter digestibility coefficient (0.7 vs 0.6). The concentrations of acid detergent fiber (ADF), sulphuric acid solubulized lignin, and tannin (soluble and condensed) were lower (P < 0.05) in D. cinerea than in A. etbaica fruits. A. etbaica fruits, however, contained higher amounts of Na, K, Fe, and Zn concentrations than D. cinerea fruits. Dry matter intake was markedly higher in supplemented groups than in the control group without supplement. Similarly, body weight gain in the control group was negative and lower (P < 0.05) than any of the supplemented groups. During the course of the experimental period (120 days) the group placed in the 1.5% D. cinerea fruit diet gained 2.6 kg whereas the control group lost 2.0 kg. Thus, the difference between these two groups was 4.6 kg, which suggests about 22.5% increment of the goats' initial body weight. N retention was negative for the control group and varied little among the remaining treatment groups. Dressing percent increased with increased level of either type of fruit supplement, the highest (51.8%) being achieved at the 1.5% D. cinerea level. There was no difference in bone tissue across treatment groups. D. cinerea fruit intake also resulted in juicy/watery flavor and tender carcass. D. cinerea fruits appeared to have no adverse effects when included at the highest level (1.5%) and could be collected and stored as dry season supplement to smallholder goats. This study shows that poor farmers can increase goat performance substantially through supplement feeding with wild fruits. Areas in Ethiopia originally set aside for provision of ecological services and biodiversity protection can also be used for wild fruit production and feeding of small stock. The effect of increasing D. cinerea fruits above the 1.5% body weight level should be a focus of future investigation. Further work on deactivation mechanism of tannins is required for A. etbaica fruits included at levels higher than 1.0%.