考虑风险价值的不确定性水资源优化配置

保障区域农业用水的可持续发展,对水资源进行优化配置至关重要。由于粮食主产区水资源配置过程中存在许多不确定性因素,在追求最小用水成本时,也存在着较大的风险,因此该文以三江平原涵盖的七台河、佳木斯、双鸭山、鹤岗和鸡西5个重要粮食主产区为研究区域,以区间两阶段随机规划模型为基础,引入风险偏好,构建地表水和地下水优化配置模型。结果表明,双鸭山和鸡西的配水过程中地表水缺水量很大,主要开采利用地下水;佳木斯作为粮食生产面积较大的行政区,需要外来水进行补给;七台河和鹤岗的种植面积较小,综合考虑引水成本和粮食收益,引用较少的外来水来降低成本;最后得出不同来水水平下,各种风险偏好下水资源优化配置的最小成本的变化规律,即在低来水水平下,用水成本从344.2×108~355.4×108元增加到411.5×108~430.7×108元;在高来水水平下,总用水成本从422.5×108~435.3×108元降低到351.7×108~365.3×108元;在中来水水平时,总用水成本则呈现出先增加后减少的规律。该模型兼有区间两阶段和风险价值模型的特点,综合衡量成本和风险,可有效节约用水成本,并能增强水资源系统规避风险的能力,并以佳木斯2014年实际用水为例,计算得到相对误差在15%以内,较为真实地反映水资源优化配置过程中的不确定性和风险性,为提高水资源利用效率和区域水资源规划管理提供依据。     

奶牛分子育种专题学习网站的建设构想

阐述了建设奶牛分子育种专题学习网站的意义和构想,规划了网站的主要内容和发展方向,为相关专业的研究者和从业人员提供参考。     

黄淮海平原农业战略区划与布局研究

许多学者对黄淮海平原农业区划进行过大量研究, 但定量化的研究尚不多见。本文在对黄淮海平原301县(区)大量调查的基础上, 综合黄淮海平原的自然资源条件、主要农作物产量及农业总产值等指标, 通过定性与定量结合, 对其进行了农业总体战略区划与布局。将黄淮海平原区划为高产区、中低产区两大类产区, 高产区又细分为粮食优势产区、棉花优势产区、油料优势产区、粮棉优势产区、粮油优势产区、棉油优势产区、粮油棉优势产区7个优势产区。在此基础上对各小区进行了具体布局研究, 这对整个黄淮海平原农业发展具有战略指导及理论意义。     

Dominance genetic and maternal effects for genetic evaluation of egg production traits in dual-purpose chickens

• 1.?A study was conducted to study direct dominance genetic and maternal effects on genetic evaluation of production traits in dual-purpose chickens. The data set consisted of records of body weight and egg production of 49 749 Mazandaran fowls from 19 consecutive generations. Based on combinations of different random effects, including direct additive and dominance genetic and maternal additive genetic and environmental effects, 8 different models were compared.

• 2.?Inclusion of a maternal genetic effect in the models noticeably improved goodness of fit for all traits. Direct dominance genetic effect did not have noticeable effects on goodness of fit but simultaneous inclusion of both direct dominance and maternal additive genetic effects improved fitting criteria and accuracies of genetic parameter estimates for hatching body weight and egg production traits.

• 3.?Estimates of heritability (h²) for body weights at hatch, 8 weeks and 12 weeks of age (BW0, BW8 and BW12, respectively), age at sexual maturity (ASM), average egg weights at 28–32 weeks of laying period (AEW), egg number (EN) and egg production intensity (EI) were 0.08, 0.21, 0.22, 0.22, 0.21, 0.09 and 0.10, respectively. For BW0, BW8, BW12, ASM, AEW, EN and EI, proportion of dominance genetic to total phenotypic variance (d²) were 0.06, 0.08, 0.01, 0.06, 0.06, 0.08 and 0.07 and maternal heritability estimates (m²) were 0.05, 0.04, 0.03, 0.13, 0.21, 0.07 and 0.03, respectively. Negligible coefficients of maternal environmental effect (c²) from 0.01 to 0.08 were estimated for all traits, other than BW0, which had an estimate of 0.30.

• 4.?Breeding values (BVs) estimated for body weights at early ages (BW0 and BW8) were considerably affected by components of the models, but almost similar BVs were estimated by different models for higher age body weight (BW12) and egg production traits (ASM, AEW, EN and EI). Generally, it could be concluded that inclusion of maternal effects (both genetic and environmental) and, to a lesser extent, direct dominance genetic effect would improve the accuracy of genetic evaluation for early age body weights in dual-purpose chickens.

     

Genotype disclosure in the genomics era: roles and responsibilities

Disclosure of affected breed without disclosure of major progenitors has been the usual practice in scientific papers reporting recessive heritable disorders of cattle. Before molecular genetics, carrier identity could not be used by breeders to control causal mutations because phenotypically normal heterozygotes among genetically related animals could not be detected other than by test mating. Accurate, low‐cost DNA tests fundamentally changed this situation. Genomics can provide relief from the old problem of emerging recessive disorders in cattle breeding, but greater transparency of genotype data between breeders is necessary to fully exploit the opportunities for cost‐efficient genetic disease control. Effective control of several recessive disorders has been demonstrated in Angus cattle, based entirely on voluntary DNA testing by breeders but mandatory public disclosure of test results and genotype probabilities for all registered animals. When a DNA test is available, major progenitors (particularly bulls from which semen has been distributed) should be identified and disclosed concurrently with the affected breed. As a minimum, whenever possible the closest common ancestors in the pedigrees of the parents of homozygous mutants should be disclosed after confirmation of carrier status. Progenitor disclosure in scientific publications should occur in cooperation with breed societies, which should have the opportunity to advise breeders and initiate management programs before scientific publication. Unless properly managed, genomic enhancement of animal selection using SNP markers may increase inbreeding, co‐ancestry and emergence of recessive disorders. The information systems and genotype disclosure policies of some breed societies will be increasingly challenged, particularly with accelerating mutation discovery using next‐generation sequencing.     

Recommendations for designing and conducting veterinary clinical pathology biologic variation studies

The recent creation of a veterinary clinical pathology biologic variation website has highlighted the need to provide recommendations for future studies of biologic variation in animals in order to help standardize and improve the quality of published information and to facilitate review and selection of publications as standard references. The following recommendations are provided in the format and order commonly found in veterinary publications. A checklist is provided to aid in planning, implementing, and evaluating veterinary studies on biologic variation (Appendix  S1 ). These recommendations provide a valuable resource for clinicians, laboratorians, and researchers interested in conducting studies of biologic variation and in determining the quality of studies of biologic variation in veterinary laboratory testing.     

高效微生物杀虫剂对蚊虫的杀灭作用

新疆阿勒泰北屯地区位于额尔齐斯河下游,夏季蚊虫泛滥,严重威胁当地人民的身体健康.本研究跟踪调查了各种水体的幼蚊滋生情况,确定了幼蚊发生的2个高峰期分别出现在5月下旬至6月上旬及6月下旬至7月上旬,同时确定了洪水型积水、排碱渠积水和漫灌林带积水是幼蚊高发的孳生地类型.采集并对蚊虫样品进行形态学鉴定,确定了该地区的优势蚊种为刺扰伊蚊Aedes vexans.用苏云金芽胞杆菌以色列亚种Bacillus thuringiensis subsp.israelensis(Bti)水剂对该蚊种进行了室内生测,其LC50和LC90分别为0.055和0.198 mg/L.分别选取3种高发孳生地的3处积水进行野外试验,发现48 h后该药剂对幼蚊的杀灭率均在96％以上,对大面积孳生地也有很好的杀灭作用.监测显示成蚊出现的高峰时间是每年的6月上旬至6月中旬及7月中旬至7月下旬.连续施药3年后,2013年的成蚊数量相比2011年时下降幅度超过50％.本研究对于北屯地区蚊虫的进一步控制以及Bti制剂在新疆的推广有重要的意义.     

Suitability of tef varieties in mixed wheat flour bread matrices: A physico-chemical and nutritional approach

Wheat flour replacement from 0 to 40% by single tef flours from three Ethiopian varieties DZ-01-99 (brown grain tef), DZ-Cr-37 (white grain tef) and DZ-Cr-387 (Quncho, white grain tef) yielded a technologically viable ciabatta type composite bread with acceptable sensory properties and enhanced nutritional value, as compared to 100% refined wheat flour. Incorporation of tef flour from 30% to 40% imparted discreet negative effects in terms of decreased loaf volume and crumb resilience, and increase of crumb hardness in brown tef blended breads. Increment of crumb hardness on aging was in general much lower in tef blended breads compared to wheat bread counterparts, revealing slower firming kinetics, especially for brown tef blended breads. Blended breads with 40% white tef exhibited similar extent and variable rate of retrogradation kinetics along storage, while brown tef-blended breads retrograded slower but in higher extent than control wheat flour breads. Breads that contains 40% tef grain flour were found to contain five folds (DZ-01-99, DZ-Cr-387) to 10 folds (DZ-Cr-37) Fe, three folds Mn, twice Cu, Zn and Mg, and 1.5 times Ca, K, and P contents as compared to the contents found in 100% refined wheat grain flour breads. In addition, suitable dietary trends for lower rapidly digestible starch and starch digestion rate index were met from tef grain flour fortified breads.     

茄子重要性状表型多样性及其在育种研究中的应用

调查分析29份茄子种质资源的8个数值型性状和10个非数值型性状指标。结果表明：29份材料的变异系数变化范围为0.090～0.568,其中叶长/叶宽的变异系数最小,萼片色变异系数最大;遗传多样性指数的变化范围为0.401～1.529,其中花瓣色遗传多样性指数值最小,茎色的遗传多样性指数最大;7个非数值型性状与抗青枯病的相关性分析结果显示,叶缘深度、叶脉色、茎色、萼片色、花瓣色、果形与田间青枯病病情存在一定的正相关性,嫩茎茸毛数量与田间青枯病发病情况呈负相关。本研究结果为茄子田间选育种研究提供可靠的依据。     

不同栽培措施对青贮玉米产量和营养品质的影响

采用随机区组设计和“3414”最优回归设计,研究青贮玉米不同种植密度、收获期和施肥水平对产量和营养品质的影响。结果表明：不同种植密度、收获期和施肥水平均极显著影响青贮玉米的产量和营养品质。其中,氮肥对青贮玉米的鲜、干生物产量的提高及青贮玉米营养品质、饲用价值的提高贡献最大,其次是磷肥,钾肥的影响较小。建立了氮、磷、钾肥和青贮玉米鲜、干生物产量,蛋白质产量,中、酸性洗涤纤维产量,脂肪产量的回归数学模型。得出了青贮玉米新饲玉14号在海南中等肥力土壤上的适宜种植密度为7.50～9.00万株/hm2;最佳收获期是籽粒乳熟中期; 预测出了获得青贮玉米最大鲜、干生物产量,蛋白质产量,中、酸性洗涤纤维产量,脂肪产量时所需氮、磷、钾肥的施用量。