扁桃实生后代花器官结构与开花结果习性研究

以13株扁桃自然实生后代为试材,研究了各实生后代的开花物候期、花性状和自然坐果率,以探究自然生长条件下扁桃实生后代的开花结果习性。结果表明:在阿拉尔垦区,扁桃各实生后代开花物候期集中在3月下旬与4月初,花期8~13 d;花冠直径、雄蕊数目、花粉数量、花粉生活力、自然坐果率均存在极显著差异:S3花冠直径最大,达到47.90 mm;S1、S2和S4雄蕊数目最多,达到45枚;S3单花药花粉量最多,达到5 611粒;S1花粉生活力最高,为93.17%;S4自然坐果率最高,为10.59%。     

胡萝卜雄性不育株的发现及其形态特征

对田间发现的胡萝卜雄性不育株作了调查与观察,并与可育株作了形态特征比较。结果表明：（１）胡萝卜雄性不育株占群体总株数的０．７８６％。（２）不育花花瓣为绿色,雄蕊为绿色瓣花型,不完全花瓣状,无花丝,花粉;花柱,柱头及子房完全被花瓣状结构所包裹,不易被发现。可育花花瓣为白色,花丝细长,白色,白色花药肥厚,布满花粉;花柱、柱头及子房明显。（３）观察至不育株育性对温度具敏感性。     

三元杂种及回交后代的遗传性状和细胞学研究

三元杂种[陆地棉×(亚洲棉×比克氏棉)]的回交后代BC4F1发生疯狂分离,在各个性状上都表现出特殊的变异类型,在育性上分离出三种类型可育株,部分可育株,不育株。对这三种类型和三元杂种F1花粉母细胞减数分裂的观察表明,三元杂种F1及回交后代的不育株减数分裂表现异常,大多染色体不能联会配对,以单价体的形式存在,且有落后染色体、三价体、四体环的出现,在末期形成了不正常的四分孢子和多分孢子,这是不育的主要原因;部分可育株,大部分染色体联会配对成棒状二价体,个别为单价体;可育株染色体配对正常,能形成可育的花粉粒。     

水稻三明显性核不育基因的初步鉴定

2001年在福建省尤溪县西城镇凤元村进行两系核不育系育性鉴定时, 在SE21S/Basmati 370组合编号为S221的800多株F₂代分离群体中发现1株与其他不育株的花粉败育形态不同的植株。经测交、回交、姐妹交的后代育性分离调查, 不育株与可育株呈1︰1分离, 以不育株为母本与普通品种配制杂交组合, 其后代育性呈1︰1分离, 可育株后代分离不出不育株, 表明S221不育性受核内1对显性不育基因控制。     

陆地棉、亚洲棉与比克氏棉杂种F1及回交后代的育性研究

三元杂种 [(亚洲棉×比克氏棉 )×陆地棉 ]及其反交的回交后代在性状上发生疯狂分离 ,在育性上分离出 3种类型 :可育型、不完全可育型、不育型。对这 3种类型及三元杂种F1减数分裂及其花粉的形成过程观察表明 ,三元杂种F1及回交后代的不育型 ,不育的根本原因在于减数分裂中期染色体不能正常配对 ,引起部分染色体滞后及染色体不均等分配 ,从而产生多分孢子和微核 ,最终导致不育花粉的产生 ;不完全可育型 ,大部分染色体联合配对成二价体 ,仅个别为单价体 ,这些单价体在后期随机向两极分离 ,产生的二分孢子有的正常 ,有的不正常 ,进而形成的花粉粒仅个别正常 ;可育株染色体配对正常 ,因而形成的花粉粒可育     

水稻显性雄性核不育基因鉴定初报

1978年我所用栽野型组合(萍矮58×华野)F_2中的无花粉型不育株与反交组合(华野×萍矮58)F_4中的正常株杂交,后代出现典败型变异株。经13个世代观察,该不育材料的测交、回交、姊妹交(不育株×可育株)F_1分离出的不育株与可育株呈1∶1;可育株自交后代育性不分离;“不育株”幼穗分化期在高温下(白天平均温度30℃以上)有部分结实,     

棉花核不育系豫98-8A育性遗传分析

为了阐明1999年从转基因后代遗传群体中发现的1株雄性不育植株不育基因的遗传规律及其与现有不育基因的等位性,采用表型观察测量,以及经典的自交和测交手段,研究了该不育材料败育性状的遗传规律。花器官形态特征调查表明：不育株花柱长和花柱外露长度均明显高于同质系的正常可育株,而每朵花的子房直径及花药数量没有明显差异。遗传分析表明：杂合体可育株自交,后代不育株与可育株呈3:1分离,不育株与杂合姊妹可育株测交,不育株与可育株呈1:1分离,表明该核不育材料受隐性单位点控制;与阆A(msc1)、洞A(msc3)等育性位点杂合可育株分别杂交,其F1代单株育性均得到恢复。由其F1代产生的F1:2家系中均出现不育株与可育株呈1:3和7:9两个育性分离群体,表明该材料败育基因为不同于阆A、洞A的不育基因位点。     

甘蓝型油菜隐性胞核不育两型系花粉与外源花粉竞争能力研究

甘蓝型油菜胞核不育两型系117AB在先授花恢花粉，1－48小时后授以可育株花粉的条件下，其异交率为45.75％－70．83％，比对照增加3．89％－28．97％，在先授可育株花粉，1－48小时后再授以花恢花粉时，其异交率为41．29％－15．77％，比对照减少0．75％－26．09％，该类材料不存在异品种优先授精现象，而且可育株花粉比花恢花粉有更强的竞争能力，其竞争优势系数为1．13-1．73之间，平均值为1．49，在制种中无论何种行比，不拔可育株，后代将不能作为种子用。     

我国北方荷兰豆良种繁育技术

荷兰豆的花为总状花序，自叶腋生出第一花序，着生于7～18节的花轴上。每一花梗着生1～3朵花，极少数为4～6朵，一般为两朵。花冠白色、粉色、紫色。花萼钟型、萼片5枚，蝶型花冠，旗瓣圆型，翼瓣龙骨瓣贴生。雄蕊10枚，分为两体，9枚合生，1枚单生。每个荚果内有种子2～10粒。种子嫩时含水分较多，因而干燥后皱缩。     

轮回选择对矮败小麦生理及产量性状的影响

对矮败小麦回交、杂交后代可育株、杂交父本或回交亲本的叶绿素含量的相对比值(SPAD值)以及叶面积系数的测定,抗病性、农艺性状的观察结果表明:部分矮败后代可育株叶绿素含量的相对比值高于回交或杂交亲本,部分矮败小麦回交2代与新品系杂交后代可育株叶面积系数高于父本;部分矮败小麦回交、杂交后代可育株白粉病、锈病抗性高于回交亲本;部分矮败材料回交、杂交后代穗部产量性状有超亲优势.     

水稻质核互作孢子体雄性不育性的基因分析

把花粉育性划分为可育、染败、圆败和典败四种类型,对三种不同细胞质来源的四个水稻雄性不育系的质核互作雄性不育性进行基因分析。结果表明,野败珍汕97A、野败二九矮4A、冈比亚卡二九矮7A 和毛早壳八四早8A 的质核互作雄性不育性均由两对隐性育性恢复基因 rf_1 rf_1 rf_2 rf_2控制,属孢子体不育类型。IR24具有相应的两对显性     

Cytological relationships among Eumelilotus species analysed using cytological observations of interspecific hybrids obtained by in vitro culture

Interspecific hybrid plants between Melilotus altissima (yellow flowers) and either M. alba (white flowers) or M. taurica (white flowers) and between M. suaveolens (yellow flowers) and M. wolgica (white flowers) which were inviable because of heavy chlorosis, were grown successfully by in vitro culture and reached the flowering stage. Pollen fertility of hybrid plants between M. altissima and M. alba was about 46% whereas hybrids between M. altissima and M. taurica and between M. suaveolens and M. wolgica showed about 25% and 18% of pollen fertility, respectively. All F₁s did not set any selfed seeds. Observing the pairing of chromosomes at metaphase I in the hybrid plants, it was revealed that the genomes of M. altissima and M. alba differ by a reciprocal translocation. This result could account for the partial sterility of pollen in the F₁ hybrids. On the other hand, hybrid plants between M. altissima and M. taurica and between M. suaveolens and M. wolgica showed normal pairing of chromosomes though pollen fertility of the hybrids was very low, suggesting that low pollen fertility was controlled by sterility gene(s). These results demonstrate that M. altissima and 7 other species of the subgenus Eumelilotus share the same chromosomal constitution. The only exception, M. alba, differs from the other 8 species by a segmental interchange. This revised version was published online in July 2006 with corrections to the Cover Date.     

‘曹州’木瓜传统栽培类型及特异种质花粉生活力研究

为研究‘曹州’木瓜不同栽培类型及特异种质花粉生活力的差异,用离体培养法测定10个‘曹州’木瓜花粉生活力,探索不同种质、不同花性间花粉生活力的差异。结果表明：不同种质木瓜花粉萌发速度存在一定的差异,‘玉兰’、‘剩花’、‘细皮’、‘豆青’、‘常青’、‘小狮子头’、‘矮化’木瓜花粉检测最佳时间为培养3 h,‘佛面’、‘大狮子头’和‘梨形’木瓜为培养6 h。完全花和败育花花粉生活力差异不显著;‘曹州’木瓜花粉生活力较好,萌发率值集中在80%左右,种质间存在显著差异,最低萌发率为42.9%,最高萌发率为86.1%。     

粳稻恢复系宁恢3-2育性恢复

两套粳稻雄性不育系(A)及其保持系(B)分别与宁恢3-2(R)杂交、回交、自交、获得两个组合的 F_1(A/R)、B_2(A//A/R)、B_2′(A//B/R)、F_2和 F_3,以花粉育性和种子育性作为恢复度指标,研究宁恢3-2育性恢复力的遗传。 结果表明,BT 六千辛 A 和 L 平壤3号 A的花粉以染败为主,在光学显微镜下不易区分分离世代植株中可育和不育花粉,故不宜用花粉育性作为恢复度指标进行遗传分析。以种子育性为指标,发现两个不育系是配子体不育类型,宁恢3-2对它们的育性恢复力是由一对显性恢复基因控制的。     

Expression of male sterility in alloplasmic Brassica juncea with Erucastrum canariense cytoplasm and the development of a fertility restoration system

An alloplasmic mustard, Brassica juncea, has been synthesized by placing its nucleus into the cytoplasm of the related wild species Erucastrum canariense to express cytoplasmic male sterility. To achieve this, the sexual hybrid E. canariense (2n=18, E^cE^c) ×Brassica campestris (2n= 20, AA) was repeatedly backcrossed to B. juncea (2n= 36, AABB). Cytoplasmic male‐sterile (CMS) plants were recovered in the BC₄ generation. These plants are a normal green and the flowers have slender, non‐dehiscing anthers that contain sterile pollen. Nectaries are well developed and female fertility is > 90%. The fertility restoration gene was introgressed to CMS B. juncea from the cytoplasmic donor E. canariense through pairing between chromosomes belonging to B. juncea with those of the E. canariense genome. The restorer plants have normal flowers, with well‐developed anthers containing fertile pollen. Meiosis proceeds normally. Pollen and seed fertility averaged 90% and 82%, respectively. F₁ hybrids between CMS and the restorer are fully pollen fertile and show normal seed set. Preliminary results indicate that restoration is achieved by a single dominant gene. The constitution of the organelle genomes of the CMS, restorer and fertility restored plants is identical, as revealed by Southern analysis using mitochondrial and chloroplast probes atp A and psb D, respectively.     

The breeding system of rubber (Hevea brasiliensis): an evaluation of controlled hand pollination methods

Summary Controlled hand pollinated pistils of rubber were observed using fluorescence microscopy to assess the efficiency of the universally-employed method for the production of progeny for plant breeding. The controlled hand pollination method conducted in the morning resulted in the deposition of a mean of 15.6 pollen grains on the stigma, with no stray pollination observed. Over 36% of the pistils had the potential to set fruit.Pollinations conducted in the afternoon at the normal time of anthesis, had double the fruit set potential of morning pollinations as measured by penetration of ovules by pollen tubes. Pollinator efficiency also varied, with excessive damage to stigmas resulting in reduced pollen germination and tube growth. There were differences between clones in both female and male fertility, in the proportion of pistils with more than three carpels and in the production of small abnormal stigmas. There was no difference in pollen tube growth following self- or cross-pollination, indicating that the self-sterility mechanism of rubber operates in the ovary. Pollen could be stored for 5 days at 5°C and 75% RH with a 22% loss of fertility.     

Cytogenetic analysis of translocations in cotton

In order to create cotton translocation lines, 191 translocations were recovered as heterozygotes following combined treatment of seeds by colchicine and γ‐rays, irradiation of seeds by thermal neutrons and c‐irradiation of pollen. Cytogenetic analysis showed that chromosome translocations involving two chromosomes arose more often (180) than those involving three chromosomes (11). The heterozygous translocations were characterized by different formation and frequencies of the multivalents at metaphase I of meiosis. Only 104 translocations were characterized by a multivalent frequency of more than 0.25 per cell. Most of the translocations (156) exhibited a high meiotic index, but 11 were characterized by a decreasing meiotic index and by an increase in the percentage of tetrads with micronuclei. The pollen fertility of translocations differed significantly and varied from high fertility to pollen sterility. The high frequency of abortive pollen grains was typical for about one half of translocations studied. The translocations were made homozygous and as a result, 12 new reciprocal homozygous translocation lines were obtained in cotton.     

Primary trisomics in Moss Verbena

Summary Four, out of the maximum of 5 possible, primary trisomics have been identified karyomorphologically. These are Pseudo Normal, Slender, Semi Erect and Weak, trisomic for C, A, B and D chromosomes respectively. The trisomics are reasonably distinguishable from one another on the basis of qualitative and quantitative characters, like growth habit and rate, stem thickness, internode length, size and shape of leaves and flowers and fertility. The most common type of association at meiosis is 5II+1 I followed by 1 III+4 II. The trisomics differ in the number and type of trivalents. There is a significant increase in range and number of ring bivalents in all trisomics particularly in Slender. This is attributable to a correspondingly significant increase in chiasma frequency. The reasons for this are not clear. Anaphase segregation is ordinarily normal and pollen fertility is high except in Semi Erect in which it is correlated with segregational errors. Although, seed setting is apparently normal in all except Slender, yet germinability is very poor. Greater phenotypic effects and lesser tolerance to the addition results in trisomics for the long submedian and satellited A and medium submedian D chromosomes than for B and C chromosomes.     

Characteristics of Pollen from Transgenic Lines of Apple Carrying the Exogenous CpTI Gene

It is fundamental for gene transformation and ecosystem hazard evaluation to study the pollen characteristics of transgenic plants. In this research,the characteristics of pollen from 7-or 8-year-old transgenic apple plants carrying an exogenous Cp TI gene were analyzed. The results showed that there was no significant difference in terms of size,morphology,or exine ornamentation between the pollen of the transgenic plants and the non-transgenic control. However,the transgenic plants had more abnormal pollen grains. Of the 13 transgenic lines tested,12 had a significantly lower amount of pollen and six exhibited a significantly lower germination rate when cultured in vitro. The pollen viability of three transgenic lines was determined,with two showing significantly lower viability than the control. The transgenic Gala apple pollen grains germinated normally via controlled pollination on Fuji apple stigmas. However,the pollen tubes extended relatively slowly during the middle and late development stages,and another 8 h were needed to reach the ovules compared with the control. The gibberellic acid concentration in transgenic Gala apple flowers was lower than in the non-transgenic control during all development stages tested. The abscisic acid concentration in the transgenic flowers was lower during the pink stage,and higher during the ball and fully open stages. Microscopic observation of the anther structure showed no difference. The tapetum of the pollen sac wall in transgenic plants decomposed late and affected pollen grain development,which could be one of the reasons for the lower number of pollen grains and poor viability in the transgenic plants.     

水稻籼粳杂种IR36/Kamairazu花粉育性的遗传

检测了47个水稻籼粳杂种F₁的花粉育性，平均值为(79.9±31.2)%，其中68%组合的花粉育性低于90%。研究了代表性组合IR36/Kamairazu不同世代的花粉育性，F1的花粉育性为79.5%，其衍生的63个F₂单株的平均花粉育性为(91.0±15.7)%。花粉育性高达98.3%的F₂单株A4-3衍生的81个F₃单株的平均花粉育性为(95.9±11.1)%，而育性为61%的A4-6衍生的51个F₃单株的平均花粉育性仅为(74.3±35.2)%。在A4-3衍生的F₃中选用2个花粉育性分别为99.2%和99.5%的单株，其衍生的F4群体的平均花粉育性分别为(93.0±7.4)%和(94.9±3.5)%，而2个花粉育性均为69.2%的单株衍生的F4群体的平均花粉育性则分别为(88.5±22.1)%和(89.8±6.7)%。IR36/Kamairazu的花粉育性受多基因控制，符合多基因座单位点孢子体—配子体互作模式。在F₂、F₃和F₄群体中，平均育性水平较高的群体，单株花粉育性与小穗受精率无显著相关性，而在平均育性水平较低的群体中，花粉育性与小穗受精率呈显著或极显著正相关。