一些牧草和饲料作物的染色体数目

<正> 本文报导了203种牧草和饲料作物的染色体数目。主要是从国内外文献报导中摘录的,少部分是吉林生物研究所1978年以来对部分牧草染色体数的鉴定。为了便于查找、学     

离体组织细胞染色体加倍技术在牧草育种中的应用进展

通过对牧草离体组织细胞染色体加倍育种中的诱导剂的介绍,进一步概述了诱变剂的浓度和处理时间、染色体加倍时的选材等因素对染色体加倍的影响及倍性鉴定技术,初步探讨了牧草离体组织细胞染色体加倍技术的研究概况,并展望了离体组织染色体加倍技术在牧草育种中的应用和发展前景。     

细胞遗传学在我国牧草中的应用

细胞遗传学知识在牧草研究中已得到了广泛应用。通过研究，初步论述了一些高产优质牧草的远缘杂交、染色体核型分析、染色体组型分析、分子标记和无融合生殖方面的应用，在此基础上对我国牧草中细胞遗传学知识的发展前景作了展望，并提出了一些建议。     

高寒地区栽培牧草的生产性能和营养价值的研究

根据青海省海晏牧场的草地资源状况和畜牧业生产特点，进行了牧草栽培试验，通过两年的试验研究，间比淘汰，优选出了最适宜当地推广种植的两种各种禾本科牧草和两种豆科牧草。结果表明，４种牧草的生产性能和营养价值随栽培年限延长而升高，年间产草量差异极显著（Ｐ〈０．０１），第２年产草量比第１年高２．３￣７．９倍；笔草的营养价值，分蘖力、生长高度和越冬返青率比第１年高，且均高于天然草地牧草，由此认为，这４种牧草是     

不同熟期苦荬菜的染色体数目及核型分析

苦荬菜Lactuca indica是一种优良的牧草种质资源,熟期是苦荬菜利用的重要影响因素之一。研究对2种不同熟期的苦荬菜种子根尖细胞进行冰浴处理,染色体用醋酸洋红染色制片。染色体数目和核型分析结果表明,早熟苦荬菜和晚熟苦荬菜染色体数目均为2n=2x=18,没有差异。早熟苦荬菜核型公式为2n=2x=2m 12sm 4st;晚熟苦荬菜核型公式为2n=2x=16sm 2st,存在差异。     

基于文献计量分析的禾本科牧草染色体加倍研究进展

禾本科牧草作为家畜的重要饲草,在畜牧业和草原生态系统中有着不可替代的作用.染色体加倍是培育优良牧草品种的主要技术措施之一,目前已有大量研究致力于人工诱导禾本科牧草染色体加倍,目的在于最大限度地提高其产量、营养价值、抗逆性以及杂交种育性恢复等性状.因此,本文基于中国知网(China national knowledge ...     

新疆半干旱地区不同种类混播草地的牧草产量和营养价值研究

提高混播草地的生产力和维持其营养价值对提高新疆半干旱地区放牧家畜生产力具有重要意义。本研究选择4种牧草,以单播为对照,设置豆禾两种牧草和3种牧草进行混播,分析混播草地生产力和牧草营养价值变化。结果表明：与单播相比,混播草地不仅具有明显生物量优势,而且牧草的酸性洗涤纤维和中性洗涤纤维含量更低,粗蛋白含量、干物质消化率、干物质采食量和相对饲喂价值更高;随着生长年限的增加（2016年到2018年）,单播和混播草地牧草干物质产量、粗蛋白产量、酸性洗涤纤维、中性洗涤纤维含量均显著增加,但粗蛋白含量、干物质消化率、干物质采食量和相对饲喂价值均显著下降。     

牧草的复种轮作和混播技术

<正> 牧草的复种轮作间作是指两种或两种以上牧草相间种植。种植的两种牧草的播种期基本相同或稍有先后。例如:苏丹草与紫云英间作,籽粒苋与牧草王问作。套种在前作的生长期内,把后作播种于前作的行间。例如:墨西哥玉米与冬牧70黑麦套种、苜蓿与墨西哥玉米套种。轮作在同一地块上当一种牧草生长结束时,再种植另一种牧草。例如:在种植苜蓿5年后,将其耕翻,改种其他牧草,如苦葜菜、墨西哥玉米等。牧草的混播为了提高牧草产量,改善牧草品质,增加和培肥地力,常将几种牧草混在一起进行播种。混播技术措施为:牧草的组合特别应做到豆科牧草和禾     

人工草地绵羊放牧系统研究—载畜量试验

通过监测划区轮物条件下的放牧系统中两种载畜量的牧草生长速度，草地现存量，绵羊采食量以及绵羊生产性能等有关指标的动态变化，探讨了高低两种载畜量对系统中牧草生长，草地利用和家畜生长三方面的影响。结果表明：低载畜量仅在羊毛产量，羔羊断奶及半岁体重等三项指标上显示出一定，它方面均无显著差异。草畜平衡分析结果表明，在本试验采用的两种载畜量下，系统中牧草全年供给量均大于家畜需求量，说明系统还有潜在生产能力。     

果洛地区多年生牧草引种试验初报

在果洛地区两个试验点同时进行２５种牧草的引种试验和室内发芽试验。结果表明：１１种禾草和２种豆科牧草表现良好，６种禾草和１种豆科牧草一般，３种禾草和１种豆科牧草农现差。     

四种叶形吸虫的染色体组型分析

应用一种自创小型复殖吸虫染色体制备法，对四种常见寄生鱼类的叶形吸虫（中华叶形吸虫、鳗鲡叶形吸虫、鲶叶形吸虫和巴氏叶形吸虫）的染色体组型分析表明，它们的有丝分裂中期染色体二倍体数目均为２ｎ＝１８，且核型十分接近，即由四对较长的具近端着丝点染色体，四对较短的具近中部着丝点染色体及一对具中部着丝点的短染色体组成。但是，它们在染色体相对长度方面存在一定的差异。聚类分析显示，中华叶形吸虫和鳗鲡叶形吸虫，鲶叶形吸虫和巴氏叶形吸虫分别组成一近缘类群。根据发状科各属虫种的染色体组型资料，探讨了该科吸虫的核型进化问题。     

Variation in important pasture grasses. II. Cytogenetic and reproductive variation

Abstract

The chromosome numbers and reproductive variation of seven important pasture grasses from South Africa are compared. This comparison indicates that all these species form polyploid complexes, all reproduce both sexually and either apomictically or vegetatively, and some form of hybridization or cross‐fertilization occurs in each species. The ecological success of these species can, therefore, be attributed to the fact that they combine the advantages of polyploidy and apomixis and, at the same time, bypass the disadvantages with their hybridization potential.     

不同禽类核型似近系数聚类分析

对北京油鸡和金定鸭染色体核型进行了研究。结果表明:北京油鸡和金定鸭常染色体形态存在较大差异,北京油鸡的No.4、No.6和No.8染色体分别为st、sm型和m型染色体;而金定鸭的No.4、No.6和No.8染色体均为t型染色体;北京油鸡的Z、W染色体为m型染色体;而金定鸭的Z和W染色体分别为st型和t型染色体。此外,核型似近系数和进化距离聚类分析表明6种禽类可分为3类,Ⅰ类包括金定鸭和五龙鹅;Ⅱ类包括鹌鹑、石鸡和北京油鸡;而稚鸡单独成类,其结果与形态分类学和系统分类学大致相同。     

Chromosomal rearrangements occurred repeatedly and independently during species diversification in Malagasy geckos,genus Paroedura

We conducted a phylogenetic study through karyological data, by standard staining and Ag-NOR banding, and molecular analysis (by 12S and 16S mitochondrial rRNA genes and nuclear gene C-mos) on 11 species of Malagasy geckos, genus Paroedura, and two relatives (Ebenavia inunguis and Uroplatus phantasticus). Ebenavia inunguis and U. phantasticus had 2n = 36 telocentric elements, NORs on the first chromosome pair in E. inunguis, and on the third chromosome pair in U. phantasticus. All examined Paroedura showed NORs on the smallest chromosome pair; moreover, six of the eleven examined species show a 2n = 36 karyotype, with a pair of metacentrics and 17 telocentric pair. The remaining species exhibited karyotypes with a diploid chromosome number ranging from 2n = 31 to 2n = 38. We assume that these karyotype assemblages derived from the 2n=36 karyotype by cryptic and/or simple rearrangements, such as inversions, fissions and fusions. Furthermore, molecular and/or chromosomal data indicate that Paroedura is a monophyletic genus, in which chromosome rearrangements occurred repeatedly and independently during the specific diversification. Moreover both P. bastardi and P. gracilis in current definitions are paraphyletic assemblages of several related species, since their population proves more closely related to P. ibityensis or P. oviceps than co-specific populations.     

Germany/Australia Index of Sperm Sex Sortability in Elephants and Rhinoceros

Flow cytometric sexing of spermatozoa followed by application in artificial insemination or in vitro fertilization provides a unique opportunity to predetermine the sex of offspring and might enhance the conservation management of endangered species in captivity such as the elephant and rhinoceros. To obtain an indication of the sortability of spermatozoa from these species, the relative DNA differences between X and Y chromosome bearing spermatozoa (fresh, frozen thawed, epididymal) from three rhinoceros species [white ( Ceratotherium simum ), black ( Diceros bicornis ), Indian ( Rhinoceros unicornis )] and both elephant species, the Asian and the African elephant ( Elephas maximus, Loxodonta Africana ), were determined through separation of spermatozoa into X and Y chromosome bearing populations, using a modified high speed flow cytometer. The head profile areas of spermatozoa from all five species were measured using light microscopy. By multiplying the relative DNA differences and the head profile areas, the sperm sorting indices were calculated to be 47, 48 and 51 for white, black and Indian rhinoceros respectively. The calculated sorting index for the Asian elephant was 66. In the African elephant, we determined the highest sorting index of 76. These results indicate the practicability of flow cytometric sex sorting of spermatozoa from the tested rhinoceros species and both elephant species. The lower sorting indices in rhinos indicate that sex sorting of spermatozoa from the rhinoceros will be more challenging than in elephants.     

两个黄芪亚种染色体数目与核型分析

前人研究认为膜荚黄芪（Astragalus membranaceus（Fisch.）Bge.）与蒙古黄芪（Astragalus membranaceus（Fisch.）Bge.var.mongholicus （Bge.）Hsiao）染色体数目为2n=16。本试验采用根尖染色体常规制片方法,观察了膜荚黄芪与蒙古黄芪种子根尖有丝分裂相。结果显示：膜荚黄芪与蒙古黄芪染色体数目为2n=18,这2种植物各有4条小染色体。膜荚黄芪染色体核型公式为K（2n）=2x=18=4sm+14m,核型类型为2B型。蒙古黄芪染色体核型公式为K（2n）=2x=18=6sm+12m,核型类型为2C型。     

Progress on the taxonomic classification of Medicago species北大核心CSCD

This review investigates the disordered status of the classification of Medicago genus,both domestically and internationally. Several definitions of a taxonomic species were considered and the names and characteristics of 13 Medicago species in China are reported,together with a detailed summary of the names,life forms,chromosome numbers,pollination methods and natural distribution of about 90 Medicago species worldwide,including the classification of 14 sections and 10 subsections in Medicago. The molecular evolutionary relationships between different species,and the geographical origin of Medicago are discussed,and the genetic relationships between different subspecies in the alfalfa complex are further explained. This study puts forward a method of identifying Medicago species on the basis of deep understanding of the concept of species. A wide collection of global Medicago germplasm resources,aiming to further clarify the evolutionary relationship among different sections and different species by molecular evolution methods is proposed. This review provides a reference framework for future Medicago classification and alfalfa cross breeding. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

硬秆仲彬草杂种后代减数分裂的观察

硬秆仲彬草〔Ｋｅｎｇｙｉｌｉａｒｉｇｉｄｕｌａ（ｋｅｎｇ）Ｊ．Ｌ．Ｙａｎｇ,ＹｅｎｅｔＢａｕｍ〕是分布于我国西部的一种多年生六倍体植物。将其与犬草〔Ｅｌｙｍｕｓｃａｎｉｎｕｓ（Ｌ．）Ｌ．,２ｎ＝２８,ＳＳＨＨ〕、鹅观草（ＲｏｅｇｎｅｒｉａｋａｍｏｊｉＯｈｗｉ,２ｎ＝４２,ＳＳＨＨＹＹ）、糙毛仲彬草〔Ｋ．ｈｉｒｓｕｔａ（Ｋｅｎｇ）Ｊ．Ｌ．Ｙａｎｇ,ＹｅｎｅｔＢａｕｍ,２ｎ＝４２,ＰＰＳＳＹＹ〕３个种进行了杂交,对亲本及杂种Ｆ１代花粉母细胞减数分裂中期Ⅰ染色体配对行为进行了观察。减数分裂平均构型分别为：Ｅ．ｃａｎｉｎｕｓ×Ｋ．ｒｉｇｉｄｕｌａ２４．０８Ⅰ＋５．２８Ⅱ＋０．１２Ⅲ;Ｒ．ｋａｍｏｊｉ×Ｋ．ｒｉｇｉｄｕｌａ１７．２２Ⅰ＋１１．８１Ⅱ＋０．２８Ⅲ＋０．０８Ⅳ;Ｋ．ｒｉｇｉｄｕｌａ×Ｋ．ｈｉｒｓｕｔａ４．３２Ⅰ＋１７．４５Ⅱ＋０．５８Ⅲ＋０．２１Ⅳ＋０．０４Ⅴ。根据以上结果,结合种的形态特征,硬秆仲彬草从鹅观草属（ＲｏｅｇｎｅｒｉａＣ．Ｋｏｃｈ）拟冰草组（ＰａｒａｇｒｏｐｙｒｏｎＫｅｎｇ）中组合到仲彬草属（ＫｅｎｇｙｉｌｉａＹｅｎｅｔＹａｎｇ）是正确的。     

不同倍性燕麦的核型分析

试验采用根尖压片法分别对燕麦的3个种Avena nudibreri,A.hispanica和A.sativa的燕麦材料的染色体核型进行了分析。结果表明:Avena nudibreri的染色体数目为2n=14,其核型公式为2n=2x=14=10m+4sm(2SAT),具2对近中部着丝点染色体和五对中部着丝点染色体,其中第5对染色体短臂末端带有随体,核型属2A型;Avena hispanica的染色体数目为2n=28,核型公式为2n=4x=28=20m+8sm(2SAT),着丝点的位置有近中部着丝点和中部着丝点区,其中第10对染色体短臂末端带有随体,核型属2A型;Avena sativa的染色体数目为2n=42,核型公式为2n=6x=42=26m+16sm(4SAT),具8对近中部着丝点染色体,第12对和第17对染色体短臂末端带有随体,其余为中部着丝点染色体,染色体组型属2B型。