一些蔷薇属植物的花粉形态研究

本文通过对中国原产的蔷薇属植物中的6个种和3个月季品种的花粉,进行扫描电镜观察,对花粉形态进行了描述,探讨了有关植物在进化过程中的地位,及通过花粉形态来鉴定月季品种及其倍性的可能性。     

疏花蔷薇与现代月季品种及其杂交后代的染色体核型分析

以疏花蔷薇(Rosa laxa,2n=2x=14)和现代月季品种‘Kardinal’、‘Solidor’、‘Yuzen’(2n=4x=28)为亲本进行杂交,杂交组合疏花蔷薇בKardinal’、疏花蔷薇בSolidor’、‘Yuzen’×疏花蔷薇分别获得5株、5株和6株杂交后代。采用常规压片法,对亲本及杂交后代的染色体数目和核型进行了分析。结果显示:杂交后代中除疏花蔷薇בKardinal’组合有1株为二倍体外,其余15株均为三倍体;疏花蔷薇的核型为12m+2sm,属1A型;现代月季品种‘Kardinal’、‘Solidor’、‘Yuzen’的核型分别为28m、28m、24m(2SAT)+4sm,核型类型分别为1A、1B、2B型;疏花蔷薇בKardinal’组合的F1代包括1A、1B和2A等3种核型;疏花蔷薇בSolidor’组合的F1代包括1A和1B等2种核型;‘Yuzen’×疏花蔷薇组合的F1代包括1A、1B和2B等3种核型。根据染色体数目和形态分析结果确定,获得的三倍体后代为真杂种,但对于二倍体后代的杂种真实性不能做出判断。     

悬钩子属和蔷薇属的新植物

本文发表了山莓两个新变型和小果蔷薇一新变型,即粉红山莓Rubus corchorifolius L.f.f.roseolus Z.X.Yu、重瓣山莓R.cor-chorifolius L.f.f.Hemi semiplenus Z.X.Yu,还有重瓣小果蔷薇Rosa cymosa Tratt.f.plena Z.X.Yu et G.Z.Liu。     

29个蔷薇属植物的孢粉学研究

采用扫描电镜技术对蔷薇属25个种及4个月季品种的花粉形态进行观察分析,探讨单叶亚属及蔷薇亚属中的芹叶组、合柱组、桂味组、月季组及月季品种之间的亲缘关系。研究表明:(1)所有被测样品的花粉都为具三孔沟的N3P4C5型单粒花粉,形状包括近球形、长球形及超长球形,其中大部分都为极轴较长的超长球形,以小檗叶蔷薇(P/E=2.29)最长。(2)在疏花蔷薇、托木尔蔷薇以及重瓣黄刺玫中发现有花粉二型现象。(3)被测样品外壁纹饰主要包括条纹、孔穴-条纹及近孔网纹3类,条纹类型主要出现在芹叶组中,而孔穴-条纹类型则为蔷薇属植物较普遍的纹饰。(4)聚类分析表明,小檗叶蔷薇与其它种亲缘较远,被测月季品种与月季组关系较近,芹叶组与合柱组关系较近,桂味组中的弯刺蔷薇与其他蔷薇的纹饰有明显区别,被单独分开。     

新疆的蔷薇属植物

蔷薇果富含大量多种微生素、氨基酸,人体必需的微量元素,被誉为水果后起之秀,尤其新疆蔷薇属植物中的疏花蔷薇,喀什蔷薇,腺毛蔷薇,腺齿蔷薇,刺蔷薇,樟味蔷薇等,果大,肉厚,味甘甜,果实总氨基酸含量达3—4.5％,微量元素约10余种,其中维生素含量,一般平均高于2000毫克/100克;不同种和分布地区不同,     

辽宁东部山区主要蔷薇属植物

辽宁东部山区是我省重点林区,它包括桓仁、本溪、抚顺、清源、新宾、凤成、宽甸七县。森林属长白山森林植物区系,是温带针阔混交林的一部分,原生森林植物群落是以红松为主的针阔混交林。该区气候属温带湿润大陆性气候型,由于气候湿润、雨量充沛、土壤肥沃,适合植物生     

安徽蔷薇属植物资源及其开发利用

通过大量的实地调查、查阅文献和腊叶标本,初步查清了安徽蔷薇属植物资源,约有13种,9变种和2型.同时,列出了其主要分布地;阐述了其生物学特性、经济价值及开发利用的现状和途径.     

芸薹属植物自交不亲和性的分子机制

芸薹属植物自交不亲和性受单一位点的复等位基因控制,此位点命名为S位点,它决定柱头表面花粉识别的专一性,S位点糖蛋白基因（SLG）和S受体激酶基因（SRK)是控制芸薹属植物花柱自交不亲和性的两个关键因子,本文介绍了编码自产不亲和性的S位点的SLG,SRK和花粉S基因的鉴定,结构及功能,并对其信号传导途径的可能机制做了简要概述。     

棉属栽培种与野生种杂交的不亲和性

本文研究了棉属栽培种与野生种杂交的不亲和性,试验材料涉及5个染色体组,包括2个栽培种(陆地棉和中棉)和5个野生种(戴维逊氏棉、瑟伯氏棉、三裂棉、阿拉伯棉和比克氏棉)。以陆地棉作母本,异己花粉管在花柱中生长缓慢,有花粉管胚珠低于10%,陆地棉×戴维逊氏棉杂种胚在子叶期坏死。以中棉作母本,不亲和性主要表现在受精后的胚胎发育过程中。     

梅与山桃远缘杂交亲和性初步研究

为培育早花抗寒梅花新品种,以梅(Prunus mume)品种‘江梅’(P.mume‘Jiangmei’)、‘淡丰后’(P.mume‘Dan Fenghou’)与山桃(P.davidiana)、‘白花’山桃(P.davidiana‘Alba’)为亲本进行杂交试验,记录种间杂交结实率,观察花粉管生长,对未成熟胚进行培养。结果表明:(1)梅与山桃、‘白花’山桃杂交结实率很低,‘江梅’ב白花’山桃未结果,结实率最高的组合为‘淡丰后’×山桃,也仅有7.4%,且杂交果实的果核内部分胚干瘪、败育。(2)山桃和‘白花’山桃的花粉在梅柱头上都能正常萌发,但花粉管生长受抑制,多数花粉管到达花柱中部即弯曲、缠绕、断裂,花粉管生长过程中有大量的胼胝质产生,表现较低的杂交亲和性,但不同种间杂交亲和程度又有所不同。(3)通过未成熟胚培养获得了杂种苗。研究表明,梅与同属种杂交存在不亲和性,幼胚拯救是获得梅与李属其他种远缘杂交杂种苗的有效途径。     

小报春与岩生报春种间杂交亲和性研究

以报春花属报春花组的小报春(Primula forbesii)和指叶报春组的岩生报春(Primula saxatilis)为亲本,对种间杂交的结实性及花粉管行为进行了观察。结果表明:小报春与岩生报春种间杂交表现为不亲和,正反交组合正常结实率为0,但正交、反交组合花粉在柱头表面的萌发和花粉管伸长过程有明显差异,小报春花粉授粉4h后可以在岩生报春柱头表面萌发,但花粉管伸长的速度明显比对照组[岩生报春(P)×岩生报春(T)、岩生报春(T)×岩生报春(P)]慢,并且花粉管生长弯曲,授粉192h后花粉管仍未到达子房;岩生报春的花粉可以在小报春柱头上正常萌发,授粉48h后花粉管到达子房;4个对照授粉组合均分别于24h(短花柱为母本)、48h(长花柱为母本)时完成受精过程。研究表明,岩生报春×小报春杂交存在受精前障碍,小报春×岩生报春杂交亲和性较好,并可通过幼胚拯救的方法获得组间杂种后代;花柱长度可能是影响种间杂交结实能力的因素之一。     

Enhanced seed development in the interspecific cross Allium cepa x A. sphaerocephalon through ovary culture

Allium sphaerocephalon pollen tubes grew into styles and penetrated micropyles of Allium cepa, but ovules started to degenerate about 16 days after pollination and no seeds developed. Seeds developed in vitro in ovaries excised from flowers 4 and 7 days after pollination. Seven weeks after culture initiation, seeds had grown in 4 of 96 excised ovaries, cultured on BDS medium supplemented with GA₃. Although the culture medium supported seed maturation within excised ovaries of self-pollinated A. cepa flowers, no viable hybrid seeds were recovered from crosses with A. sphaerocephalon. Extended post-fertilization barriers may have restrained development of hybrid embryos in vitro. Ovary culture followed by in ovulo embryo rescue may be feasible for distant-species hybridization in Allium.     

Evaluation of hypotheses concerning the origin of Lotus corniculatus (Fabaceae) using isoenzyme data

Summary An isoenzyme survey was conducted for several geographically dispersed accessions of four diploid Lotus species, L. alpinus Schleich., L. japonicus (Regel) Larsen, L. tenuis Waldst. et Kit and L. uliginosus Schkuhr, and for the tetraploid L. corniculatus L., in order to ascertain whether isoenzyme data could offer additional evidence concerning the origin of L. corniculatus. Seven enzyme systems were examined using horizontal starch gel electrophoresis. These were PGI, TPI, MDH, IDH, PGM, 6-PGDH, and ME. Lotus uliginosus had monomorphic unique alleles, that were not found within L. corniculatus, at 7 loci. These loci and alleles are: Tpi1-112, Pgm1,2-110, Pgm3-82, Mdh3-68, 6-Pgdh1-110, 6-Pgdh2-98,95, and Me2-100. Other diploid taxa contained alleles found in L. corniculatus for these and other loci. The implications of the isoenzyme data to theories on the origin of L. corniculatus are discussed.Communicated by H. F. Linskens     

培养基组分及培养条件对蜡梅花粉萌发及花粉管生长的影响

采用液体培养法研究不同培养基组分和培养条件对蜡梅花粉萌发和花粉管生长的影响。结果表明:(1)PEG-4000是蜡梅花粉离体培养所必需的培养基成分,当培养基中无PEG-4000时,花粉不能正常萌发。(2)培养基内低浓度蔗糖对花粉萌发和花粉管的生长无显著影响,但随着蔗糖浓度的升高,则对花粉萌发和花粉管生长表现出强烈的抑制作用,且浓度越高,抑制效应越强。(3)培养基内其它组分分别在一定浓度范围(0～250g/L PEG-4000、0～50mg/L硼酸、0～30mg/L硝酸钙)内对花粉萌发及花粉管生长有促进作用,但超过上述高限值时则起抑制作用。(4)培养基内镁和钾的浓度对花粉萌发及花粉管生长影响不显著。研究表明,蜡梅最适花粉液体培养基组分为250g/L PEG-4000+50mg/L H3BO3+30mg/L Ca(NO3)2.4H2O,且在pH 5.5、温度15℃和600lx的光照培养条件下蜡梅花粉萌发和花粉管生长最佳。     

杂交石竹授粉受精及其胚胎发育过程的观察

以‘杂交石竹’为试验材料,利用荧光显微镜观察其授粉后花粉萌发、花粉管生长情况,采用石蜡切片法对其受精及胚胎发育过程进行观察研究。结果表明:(1)授粉后1h母本柱头上少量花粉开始萌发;授粉后4h大量花粉萌发,花粉管生长至柱头中部有胼胝质出现;授粉后6h花粉管生长至子房组织并有少量与胚珠结合;授粉后15h柱头中出现大量胼胝质,花粉管与胚珠结合数增多;授粉后24h胚珠周围出现多条花粉管,其中1条花粉管进入胚珠,部分进入胚囊的花粉管卷曲盘绕生长并产生胼胝质;精细胞与极核的融合主要发生在授粉后17~48h,与卵细胞融合主要于授粉后1~3d。(2)杂交石竹胚发育经过原胚、球形胚、棒状形胚、心形胚、鱼雷形胚和子叶形胚阶段。(3)杂交障碍表现为:只有游离的胚乳核而无胚发育的胚囊、合子未分裂、两极核未融合、球形胚败育。研究表明,杂交石竹存在受精前和受精后障碍,这是导致其结实率低的主要原因。     

Cyclomorphosis as a factor explaining success of a Daphnia hybrid in Tjeukemeer

Recent studies have shown that Daphnia hybrids are intermediate to their parental species for several life history traits, and that they combine advantageous traits of the parental species, thereby decreasing their risk of being preyed upon by planktivorous fish. In this study D. galeata, D. cucullata and their interspecific hybrid are compared with respect to cyclomorphosis and juvenile growth as a potential mechanism to avoid invertebrate predation. Helmets and tail spines are known to reduce predation risk, whereas fast juvenile growth reduces the period that Daphnia are vulnerable to predation. In laboratory cultures, I tested the hypothesis that, with regard to cyclomorphosis, juvenile hybrids are more comparable to the juveniles of D. cucullata, and with respect to growth rate, they are more comparable to D. galeata. The hybrid did not differ significantly from D. galeata in the time needed to reach 0.9 mm body length. In contrast, the relative spine and helmet length of juvenile hybrids were more comparable with those of D. cucullata, whereas in adult instars these characters were more similar to D. galeata. Thus during the first juvenile instars, the hybrids combine the relative long helmet and spine of D. cucullata, with the faster growth of D. galeata. This combination of characteristics might reduce hybrid vulnerability to invertebrate predation in field situations.     

Maturation of maize pollen in vitro

Summary Maturation of maize pollen was obtained in male reproductive structures cultured in vitro. Immature tassels containing microspores at the mid-uninucleate to late-binucleate stage of development were excised and spikelets, anthers, and/or isolated microspores were cultured on a medium capable of supporting pollen maturation. Microspore mitosis, culminating in the production of starch-filled, trinucleate pollen capable of germination, was observed after 7–15 days, depending on the genotype and stage at which the cultures were initiated. Up to 100%, 70%, and 20% of the cultured spikelets, anthers, and isolated microspores, respectively, produced mature pollen, which germinated, however, at different frequencies (i.e., spikelets, 50–70%; anthers, 5–10%; microspores, <1%). Mature kernels were produced following fertilization with pollen from cultured spikelets and anthers. These procedures provide methods for the in vitro manipulation of a significant phase of the maize life cycle.     

根尖维管组织在狗蔷薇类原球茎发生中的作用

为了解狗蔷薇(Rosa canina L.)类原球茎发生机制,以建立月季高效再生体系,探讨了根尖内部维管组织在狗蔷薇愈伤-不定根根尖膨大发育为类原球茎过程中所起作用。剪切试验发现,脱离愈伤的狗蔷薇不定根根尖不能诱导类原球茎形成;桥接培养表明,通过维管组织向根尖运输外源激素TDZ诱导类原球茎发生的效率高于共质体运输方式;TIBA(2,3,5-triiodobenzoic acid)处理限制了根尖维管组织向分生区的延伸速度,并最终影响了类原球茎发生率;在类似狗蔷薇愈伤-不定根结构的蒺藜苜蓿(Medicago truncatula Gaertn.)根段-不定根上也重现了根尖被诱导发育为绿色球体过程。由此表明,愈伤-不定根中完整的维管组织是狗蔷薇类原球茎发生的结构基础之一,揭示获得与愈伤-不定根类似的内部结构和组合模式的外植体(如毛状根),并将其视为整体进行诱导培养,是建立月季类原球茎再生体系的前提之一。