Genetic improvement of New Zealand aquaculture species: programmes,progress and prospects

Aquaculture, like terrestrial farming, cannot achieve economic and sustainable production without high performing genetic stocks tailored to the conditions under which they are grown. It is essential, therefore, that aquaculture investment includes genetics and biotechnology to adapt marine livestock to the novel conditions of intensive aquaculture and to the demanding markets into which they are sold. The return on investment in well-structured breeding programmes can be very high, and significant performance and economic gains have been demonstrated in multiple species. Many factors must be considered in designing a genetic improvement programme, including the reproductive biology of the species and the identification of realistic and commercially relevant breeding goals based on the resources and facilities available. This paper reviews the options available to aquaculturists and provides examples of how these are being applied to six aquaculture species in New Zealand: king salmon, hāpuku, kingfish, Greenshell^TM mussels, Pacific oysters and pāua (abalone).     

A correction model for conditional bias in selective mining operations

A nonlinear correction functionK(Z*) is proposed to transform any initial linear grade estimatorZ* into a conditional unbiased estimatorZ**=K(Z*) with reduced conditional estimation variance. Such a corrected estimator allows more accurate prediction of ore reserves at any level of selection performed during the mine lifetime. The correction is based upon an analytical or isofactorial representation of a bivariate distribution model of true gradeZ and its estimatorZ*. This correction model allows derivation of conditional estimation variances for both estimatorsZ* andZ** and provides a solution to the problem of change of support. A case study is presented and performance of the proposed correction model is evaluated in terms of actual conditional bias and mean squared errors. Results obtained stress the practical importance of the correction model in selective mining operations.     

贵州六盘水地区煤层气选区及勘探部署

该文对贵州六盘水地区煤层气选区从预选、钻井、试采三个阶段进行了评价，提出了各个阶段的评价原则、评价标准及结果；提出了该区煤层气勘探可望从金竹坪、松河及箐脚等3个区块取得突破的勘探部署建议。     

Selectivity of various types of salt-resistant plants for K over Na

Selectivity by whole plants for K⁺ over Na⁺ in three types (salt excluding, salt secreting and salt diluting) of salt-resistant plants was investigated. An estimating formula of Selective Absorption (SA) capacity of root systems was derived; the Selective Transport (ST n) capacities between K⁺ and Na⁺ by various parts of the three types of plants were compared. The results showed that the SA value of salt-excluding plants were higher than that of salt-secreting and salt-diluting plants, the ST1 (root:stem) value was much higher, indicating that both the capacity of selective absorption and the capacity of selective transport by root systems were strong. In salt-secreting plants, the SA value lay between salt-diluting and salt-excluding plants, while the ST1 value was the lowest, indicating that the majority of Na⁺ uptake by root systems was transported up to their aerial parts and then the surplus salt was secreted in salt glands. In salt-diluting plants, the SA value was the lowest, indicating that the majority of Na⁺ taken up by the root systems entered into plant body perhaps to satisfy the requirements for osmotic adjustment and growth, and the ST1 value lay between salt-secreting and salt-excluding plants. These data strongly indicate that the SA and ST1 values reflect the K⁺ and Na⁺ selectivity characteristics of salt-resistant plants. Therefore, the various types of salt-resistant plants would be classified by using the values of SA and ST1. We suggest that this provides a way for distinguishing various types of salt-resistant plants. Comparing the ST n values of the six species in our paper, we concluded that the selectivity of transporting K⁺ over Na⁺ into the actively photosynthesizing organs and particularly into the developing ears is extremely high. Our conclusion is in accordance with previous results that demonstrate that the capacities of selective transport by different parts of the plant for K⁺ over Na⁺ are best quantified by ST n values. The necessity, feasibility and wide-ranging applicability of the formulas for estimating SA and ST n values have been discussed in detail.     

端元可变非线性混合像元分解模型

遥感影像中混合像元普遍存在。端元固定的情况下对混合像元进行分解,很难高精度地识别影像地物。本文基于支持向量机,提出了端元可变的非线性混合像元分解模型。首先,通过构建多个支持向量机获取每个像元的优化端元集,在优化端元集的基础上运用支持向量机与两两配对方法相结合的算法获取像元组分。试验结果表明,本文提出的方法效果优于传统的多端元光谱分解法。     

星斑川鲽家系建立及遗传效应分析

星斑川鲽是优良的鲆鲽鱼类种质之一,在鲆鲽鱼类养殖产业中具有重要的地位。本研究初次收集了分布于山东半岛的4个养殖群体(日照、胶南、威海和蓬莱)的350尾亲鱼,分别测量了100尾雌雄亲鱼的体长和体质量,拟合了雌雄性亲鱼体质量和体长幂函数关系,分别为:y=0.034 2x2.843 6 (R2=0.565)和y=0.075 9x2.533 4(R2=0.753 8)。利用其中成熟的55尾雄鱼和46尾雌鱼进行人工繁殖,雌鱼平均产卵次数为4.39次、雄鱼产精次数为2.36次。其中25个杂交组合繁殖成功,建立了29个半同胞和全同胞家系。在家系生长到150 d时,对1 640尾鱼苗体质量、全长、体长和体宽4个性状进行测量。利用最小范数二次无偏估计法(MINQUE)对以上性状的方差组分进行估计,利用"加－显性"模型对生长性状遗传力进行估计,采用线性无偏预测法(Linear Unbiased Prediction,LUP)预测亲本的加性和显性遗传效应。结果显示:4个性状的遗传相关系数为0.809~0.999(P<0.01)。体质量、全长、体长和体宽4个性状的加性、显性方差分量都达到极显著水平(P<0.01),狭义遗传率为0.311~0.444(P<0.01),广义遗传率为0.377~0.525(P<0.01)。加性遗传效应预测显示:31个亲本中的6个在4个性状上同时具有极显著的正向效应(P<0.01),10个亲本具有极显著(P<0.01)或显著(P<0.05)的负向效应。显性随机效应预测显示:25个杂交组合中6个具极显著正向效应(P<0.01),8个具有极显著负向效应(P<0.01)。研究结果首次为星斑川鲽家系建立和优良苗种培育筛选出了优良的亲本和杂交组合,同时为星斑川鲽的选择育种提供了丰富的遗传指标。     

Selective chemical degradation of kerogen from Nenjiang Formation of the southern Songliao Basin

A sequential selective chemical degradation has been performed on the kerogen from the Nenjiang Formation of the southern Songliao Basin by using a series of mild chemical degradations (alkaline hydrolysis, cleavage of ether-bonds and sulfur-bonds, and ruthenium tetroxide (RuO4) oxidation). Subsequently, the GC-MS analyses are carried out on different degradation products. The results show that chemical degradations can release a great number of GC/MS-determinable biomarkers from insoluble kerogen, such as, alkaline hydrolysis products mainly comprise n-alkanes, fatty acids and alkanols; thiophene compounds are predominantly ether-bound to kerogen matrix; the products from the cleavage of sulfur-sulfur and sulfur-carbon bonds in the kerogen include fatty acids, alkanols and some n-alkanes with high carbon numbers; RuO4 oxidation products are predominantly monocarboxylic acids and α,ω-dicarboxylic acids. The distributions of main degradation products indicate that organic matter in this kerogen is predominantly derived from algae and bacteria, and that small amounts of high plant-derived organic matter are possibly combined into kerogen matrix at the late stage by sulfur bonds and other means. This study will provide an important approach for further discussing sources of organic matter in source rocks and their depositional paleoenvironments.     

提取深部铀矿直接找矿信息的相量化探新方法

本文介绍了勘查地球化学的新进展——相量化探找矿新方法及其特点、应用,并对新方法的找矿机制从理论上进行了初步探讨。