陆地棉植株上色素腺体空间分布模式的多样性及其选择

利用陆地棉全株有色素腺体与无色素腺体的品种杂交而获得的6世代群体,研究了植株13个器官色素腺体的分布.基于器官上色素腺体的有无,发现植株色素腺体的空间分布具有10种模式.每一模式代表着植株色素腺体密度的特定等级,不同模式所包含的着生色素腺体器官的种类和数量不同.同一模式中各器官的色素腺体密度与其群体平均密度值的差亦不同,据此,作者提出了色素腺体的早生器官、迟生器官、同生器官和缓生器官的概念,并运用空间分布模式,为在实践中选样或保留理想模式提出了更为可靠的方法.     

陆地棉色素腺体密度与丰产早熟性的相关及后代的遗传变异

本研究利用两个有色素腺体品种与两个无色素腺体品种,配成4个杂交组合,每组合包括P_1、P_2、F_1、F_2。在对4个组合各性状进行了世代间的方差分析后,着重研究F_24个部位及4个部位平均的色素腺体密度与19个产量因素及早熟性性状之间的相关性。结果表明,色素腺体密度与各产量及早熟性性状之间均无密切相关。在进行育种工作时,色素腺体密度可不做为必须着重考虑的因素。对遗传参数的估算结果表明,衣分的遗传力较高,单株铃数、单铃重为低到中等,单株籽棉产量和皮棉产量遗传力最低。遗传进度由高到低的变化趋势为:单株籽棉产量、单株皮棉产量>单株铃数>单铃重、衣分。     

一种鉴定4种根结线虫的PCR方法

根结线虫(Meloidogyne spp.)是威胁全球农业生产的重要病原物,每年给农业生产造成巨大的经济损失.利用两对引物#C2F3/#1108和MI-F/MI-R建立了一种适用于4种根结线虫分子鉴定的技术.结果表明:引物#C2F3/#1108可将根结线虫分为南方根结线虫或爪哇根结线虫、花生根结线虫和北方根结线虫;引物MI-F/MIR可用于特异性区分南方根结线虫和爪哇根结线虫.     

Clinical and ultrasonographic findings in the mammary gland of sheep

AIM: To compare clinical and ultrasonographic findings and assess the value of ultrasonography for evaluating the structure and condition of the teat and teat canal of sheep.

METHODS: The mammary glands of 30 lactating ewes were examined clinically and using ultrasonography. The distance from the teat tip to the ground was measured and diagnostic images of the body of the gland, gland cistern and teat cistern were obtained using an 8.5 MHz frequency ultrasonic transducer. A California mastitis test (CMT) and bacteriological culture were performed on milk samples collected from each half of each udder.

RESULTS: Udder parenchyma and teats were palpably normal in 27/30 (90%) ewes. Milk clots or abnormalities were evident in 4/30 (13%) udders, lesions in the glandular parenchyma and/or teats were evident by palpation in 3/30 (10%), and pathogenic bacteria were cultured from 2/30 (7%). In both of the latter cases, mastitis was diagnosed based on clotted and discoloured appearance of milk and highly positive CMT reactions. Ultrasonographic examination in these udders revealed non-homogenous regions in the glandular tissue and alternating areas of hyperechogenic and hypoechogenic tissue. Overall, highly positive CMT reactions were evident in milk from 14/30 (47%) left halves and 9/30 (30%) right halves (p=0.02). No relationship between teat-to-ground distances and CMT results was evident (p>0.05). Teat canal lengths ranged from 5.7–10.3 mm (mean=8.6; SD=1.3 mm) and the widths from 1.8–3.1 mm (mean=2.3; SD=0.4 mm). Milk sampled from ewes that had long (≥9 mm) or wide (≥2 mm) teat canals was highly positive to the CMT in 75% and 83% of cases, respectively.

CONCLUSIONS: Ultrasonographic measurements of the length and width of the teat canal appeared to correlate with CMT results. The use of ultrasonography in evaluating the health of the udder of small ruminants holds promise for the future.     

鸡胚垂体生长激素细胞的发生及其变化

为研究鸡胚垂体中生长激素细胞的发生及其在发育过程中的变化 ,分别在鸡胚发育的第 3 5～ 2 0 5天采集鸡胚垂体 ,用免疫组织化学方法研究鸡胚垂体中生长激素细胞的发生和细胞形态、数量、在垂体中的分布特点和在发育过程中的变化。结果表明 ,鸡胚发育中期第 9 5天可观察到少量的生长激素阳性细胞散在分布于垂体后叶 ,细胞多排列成索状或团状 ,细胞之间边界不清 ,细胞核较大。在鸡胚发育的第 12 5天以后 ,生长激素细胞的细胞浆与细胞核比值逐渐变小 ,且均匀分布于腺垂体的后叶。生长激素细胞数在鸡胚发育的第 12 5天之后显著升高 (P <0 0 1) ,在鸡胚发育的第 16 5天 ,生长激素细胞占垂体细胞总数的 9 4 %。以上结果证明鸡胚垂体中生长激素细胞增殖和分化过程主要发生在发育的中期至出壳之前 ,而生长激素细胞的分泌功能在鸡胚发育的后期最为活跃。     

日本龟蜡蚧成虫蜡腺及精子的超微结构观察

日本龟蜡蚧是经济林的重要害虫之一,近些年来为害极为严重。为了对该蚧虫的综合防治和蚧虫分类奠定理论基础,作者从1987年开始进行了一些生理、结构方面的基本性研究。1、采用透射电镜技术,对该蚧的精子结构进行了观察,其结构与其他昆虫大不相同,精子呈丝状。成束存在,每束约16根,精子前段螺旋状,中段粗,为有核区,后段逐渐变细,内部有核区和呈环状排列的微管,没有发现顶体,中心粒,线粒体等结构;2、采用扫描电镜对该蚧的蜡腺外型结构进行了观察,并将其分为10种类型。     

番鸭(Cairina moschata)甲状腺的显微与亚微结构

番鸭甲状腺实质由大小不一、近似球形的滤泡组成,其上皮细胞呈低立方形至扁平形.电镜下的滤泡上皮细胞,胞质内存在多量由被吞饮的胶状质与溶酶体相结合的胶质滴,线粒体外围有以核糖体规律排列的粗面内质网,网腔内多被低密度的无定形内容物所扩大.番鸭甲状腺实质存在滤泡旁细胞(C细胞).经Ehrlich苏木素染色的滤泡旁细胞呈球形、体积大、染色较浅,单个散在或2个并列位于滤泡外围的结缔组织内,不与滤泡腔接触,可明显与滤泡上皮细胞相区别.