山下黑猪与鲁莱黑猪正反交F1代杂种优势的估计

旨在估计山下黑猪和鲁莱黑猪正反交F₁代杂种优势，筛选出合适的杂交方式，以提高优质肉猪的生产效率，满足人们对于优质猪肉的需求。本研究在山下黑猪（164头）和鲁莱黑猪（69头）及其正（6头山下黑猪♂×25头鲁莱黑猪♀）、反（3头鲁莱黑猪♂×35头山下黑猪♀）交4个群体中测定了生长肥育、体尺外貌（75～110 kg）、繁殖和胴体肉质（90～115 kg）4大类共43个性状，比较了这些性状在群体间的差异，并估计了正反交F₁代的杂种优势。结果表明，山下黑猪的生长肥育和体尺性状较好，鲁莱黑猪的繁殖和肉质性状较好，正反交群体介于它们之间。正交群体的繁殖性能优于反交群体，但生长肥育性能比反交差。由于这4个群体的母猪都是纯种，因此繁殖性状没有表现出明显杂种优势。除膘厚、胸椎数、45 min pH和剪切力无显著的杂种优劣势外，大部分胴体性状和肉质性状有明显的杂种劣势。生长肥育性状的杂种优势在正反交群体中的表现不一致，反交群体表现出显著杂种优势，而正交则无明显的杂种优势。本研究估计了山下黑猪和鲁莱黑猪正反交的杂种优势，为筛选山下黑猪和鲁莱黑猪的最佳杂交方式奠定基础。     

舍饲育肥条件下凉山半细毛羊的产肉性能研究

对三组凉山半细毛羊的 4月龄断奶公羔 ,用 3种不同的补饲水平 (Ⅰ、Ⅱ、Ⅲ )进行舍饲 ,分别于 6月龄和 8月龄对各组肥羔进行屠宰测定。结果表明高营养水平组 (Ⅰ )的羔羊 6月龄和 8月龄体质量、日增质量极显著高于低营养水平组 (Ⅲ ) (P <0 .0 1) ,显著高于中等营养水平组 (Ⅱ ) (0 .0 1

0 .0 5 )。凉山半细毛羊肌肉中氨基酸种类齐全 ,含量较丰富 ,其中必需氨基酸的总量达到 2 6 .15 %。     

百脉根种子硬实处理与耐藏性的探讨

地百脉根种子硬实用不同方法处理和对不同贮藏时间种子耐藏性的测定结果表明：贮藏１年种子含硬实率５９．３％。经擦破种皮或硫酸浸种处理，硬实率明显下降，发芽势，发芽率显著提高；种子随贮藏期的增长，硬实率明显下降，其发芽势，发芽率，活力指数以及直播出苗率，幼细苗存活率等亦随贮藏时间的延长而下降；种子电导值则随贮藏时间的延长而增大。     

高原瘦肉型猪肥育性能与胴体品质分析

选择59头高原瘦肉型猪，断奶后每个血统选用5～9头公猪为一组，经育肥达90kg体重屠宰，测定其胴体性状和胴体品质，测定结果表明全期日增重均在500g以上，但各世代有差异，其胴体品质较之互助猪有了明显提高。     

水稻籼粳核质核杂种研究初探

籼质粳核核质杂种配普通籼稻,粳质籼核核质杂种配普通粳稻,以及这两种核质杂种互交F1,称之为核质核杂种.研究表明,核质核杂种既保持了或基本保持了籼粳稻亚种间的杂种优势水平,又克服了籼粳稻亚种间不亲和的问题、植株超高问题和不能正常抽穗等问题.探索了一条亚种间杂种优势利用的新途径.     

Evaluation of Five Most Commonly Grown Cotton Cultivars (Gossypium hirsutum L.) Under Mediterranean Conditions: Productivity and Fibre Quality

Studies were conducted in four regions of central Greece (Larisa, Karditsa, Livadia, Thiva), to evaluate the productivity and fibre properties (fibre strength and fibre length) of the five most commonly grown cotton cultivars in these regions. The experiments lasted for 6 years (1995–2000). All the characteristics tested were strongly influenced by the factors ‘year’, ‘cultivar’ and ‘region’. Significant cultivar × region, year × cultivar, region × year and cultivar × region × year interactions occurred for all the characteristics studied. The cultivar Alegria had the highest seed‐cotton and lint yield, while Aria had the lowest ones. Both cultivars gave the highest mean lint percentage but the lowest mean boll weight (MBW). Alegria had the lowest fibre strength, while Aria had the highest. The Acala‐type cultivars, Acala SJ2 and Zeta 2, had intermediate seed‐cotton and lint yield, while Vered 171 had high seed‐cotton and satisfactory lint yield. The three cultivars mentioned above had the highest MBW and very good fibre strength. Positive correlation was observed between fibre strength and length. In spite of the fact that mean fibre length was statistically the same in all cultivars, it was influenced by the factor ‘year’, as a result of different weather conditions. The year 1996 was the most unfavourable one for seed‐cotton yield and MBW, because it was characterized by lower than average air temperatures and rather dry conditions for all study sites. The factor ‘region’, a combination of different climatic conditions and cultural practices, influenced significantly all the parameters studied.     

Use of androgenesis in intersubspecific hybrid rice breeding

Significant differences of callus induction, green plant regeneration and culture efficiency were observed among restorer lines and their hybrids in rice. Average callus induction percentage of F₁, hybrids was about twice that of their parents. Twenty doubled haploid (DH) lines that showed normal fertility with both indica and japonica CMS lines, were selected as widely compatible restorers (WCRs). TG8 derived from CPSLO17/Minghui 63 not only showed normal fertility to both indica and japonica test varieties and CMS lines, but also exhibited superior agronomic traits, in particular short plant, desired plant type, high tillerability, large panicles, good grain quality and resistance to rice blast disease. Strong heterosis for yield was observed in crosses between indica or japonica CMS lines and TG8. TG8 possessed a dominant, widely compatible gene (WCG) that was inherited from the variety CPSLO17. Results confirmed that the anther culture technique is a quick and effective way of developing widely compatible restorers in rice and that it is applicable to the direct use of intersubspecific heterosis with the three-line method.     

毛赤杨硬枝扦插技术

在毛赤杨硬枝扦插时，利用NK4、NK3进行处理，其生根率分别达到89.78%,88%。     

Estimating Combining Ability of 4x-2x Crosses in Cultivated Potatoes

Progenies derived from crosses between Solarium tuberosum and 2n pollen-Producing diploid hybrids, exhibit obvious hybrid vigor. The 2n pollen-producing clone can act as a bridge in crossing S. tuberosum and S. andigena with S. phureja. Populations from 4x-2x crosses show more unifomity and less segregation compared with that of 4x-4x crosses. The parent-offspring correlation for the traits, starch content and tuber number, is significant at 0.01 level. The regrssion equations are Y (mp-F1)=1.0 1.2x and Y (mp - F1) = 5.3 0.8x, respectively. The 2n pollen-producing clones play an impotant role in increasing tuber stach content. Estimates of the combining ability for the main yield components indicate that additive effect prodominatcs for such trais as plot yield, tuber weight per plant and starch content, whereas both additive and non-additive effects lay equal stress on mean tuber weight and non-additive effect is important for tuber number. In general, non-additive effect appears to be important in     

平潭县燕下埔沙荒风口综合治理试验初报

对燕下埔沙荒风口地段的综合治理试验结果表明：风口造林要取得成功，除了要采取必要的生物措施，更为重要的是应设置具有一定疏透度的风障以降低风沙危害，提高造林成活率。