番木瓜核型和减数分裂研究

对番木瓜核型和花粉母细胞减数分裂行为的研究表明,番木瓜染色体数目为2n=18,由9对中部着丝粒染色体组成。核型公式为2n=2x=18m。花粉母细胞减数分裂正常,在终变期和中期Ⅰ观察到9个二价体,未观察到染色体结构变异和行为异常。     

二倍体雌核发育鱼产生二倍体卵子的证据

二倍体雌核发育第 1代 (G1)产生的二倍体卵子经紫外线灭活的散鳞镜鲤精子诱导 ,无需染色体加倍处理 ,发育成二倍体雌核发育第 2代 (G2 ) ;G1 产生的二倍体卵子与雄性异源四倍体鲫鲤 (AT)产生的二倍体精子结合 ,形成新型两性可育的异源四倍体鲫鲤 (G1 ×AT)。对G2 和新四倍体 (G1 ×AT)的体细胞染色体数目、生殖细胞染色体行为及性腺结构、外形、生长速度等生物学特征进行了研究。结果表明 :G2 体细胞染色体数目为 2n =1 0 0。在 6～ 1 2月龄G2 中 ,没有发现性成熟的个体 ,组织学切片结果表明 ,G2 性腺处于卵原细胞增殖阶段 ,与 1龄G1 的性腺发育相似 ,性腺发育迟缓。对 6～ 8个月龄G2 性腺染色体制片进行观察 ,结果表明 ,G2 生殖细胞的染色体没有二价体的形成 ,只有有丝分裂的迹象 ,其有丝分裂中期不但有 2n =1 0 0的染色体分裂相 ,还有 4n =2 0 0的染色体分裂相 ,甚至有接近 8n(380 )的分裂相 ,说明 1龄G2 的性腺中存在 2n、4n等多种类型的生殖细胞 ,其中 4n的生殖细胞经正常的减数分裂后可产生二倍体卵子。核内复制 (pre meioticendoreduplication)学说可以较好地解释这种不减半配子产生的现象。新四倍体 (G1 ×AT)体细胞染色体数目为 4n =2 0 0 ,雌雄新四倍体 (G1 ×AT)具有正常的性腺发育 ,在繁殖季     

大麻染色体行为分析

以大麻不同性别的植株为材料,常规压片法观察细胞染色体行为规律。核型分析结果表明:大麻雌雄株的体细胞染色体数目均为2n=20,核型公式分别为雌株2n=2x=20=18m 2sm,雄株2n=2x=20=18m 2sm(1SAT)。雌株体细胞中有2条X染色体,而雄株只有一条X染色体和一条具有大随体的Y染色体。雌雄株核型均为2A型,为较对称核型。这一结果可为进一步研究大麻性别的分化机制提供细胞遗传学理论依据。     

美人蕉核型研究

对美人蕉体细胞染色体计数,并对其核型进行分析。结果表明,美人蕉的染色体数目为2n=18,核型公式为2n=2x=18m,属于"1A"型。     

新疆猪毛菜属植物染色体数及核型分析

以5种新疆猪毛菜属植物为材料,常规压片法制片后观察记录染色体数,并进行核型分析。实验结果表明:钠猪毛菜体细胞染色体数2n=18;浆果猪毛菜2n=2x=18=12m 6sm,属2A核型;木本猪毛菜2n=2x=18=16m 2sm,属2A核型;东方猪毛菜2n=4x=36=26m 10sm,属2B核型;长刺猪毛菜2n=4x=36=24m 4sm 8st,属2B核型。猪毛菜属植物的染色体基数为9,东方猪毛菜、长刺猪毛菜为四倍体,其它3种均为二倍体。与Бочанцев基于形态学特征建立的分组系统及各组的演化地位相比,东方猪毛菜属于原始的硬叶猪毛菜组,而本研究表明该种在核型上相对较为进化;其余3种核型地位与所属组的演化地位相符。     

同源四倍体青花菜的核型分析

以四倍体青花菜为材料,采用常规压片法进行核型分析和有丝分裂观察.结果表明:四倍体青花菜核型公式为2n=4x=36=16m+20sm(4 SAT),其中第3、4、7、8对为中着丝粒染色体,第1、2、5、6、9对为近中着丝粒染色体,第6对染色体具随体;核型类型属于2A型,为基本对称型;染色体相对长度组成为2n=36=16 M_2+20 M_1,表明该四倍体青花菜是二倍体加倍得到,为同源四倍体.在部分四倍体根尖中发现非整倍体细胞,其染色体数目变异较大;与二倍体相比,四倍体有丝分裂过程存在双核仁、体细胞配对、染色体桥等异常现象.     

毛花猕猴桃原生质体再生植株根尖染色体数目变异与细胞多核现象

对18株毛花猕猴桃(Actinidia eriantha Benth.)原生质体再生植株的体细胞染色体数做了观察,其中12株为整倍体:二倍体(2n=58)和四倍体(2n=116)各6株;另外6株为混倍体,其染色体数目变化在59～203之间。还发现原生质体再生植株有丝分裂间期细胞存在多核现象,有多核细胞的共10株,细胞核数目以双核和三核较常见,最多的有7个核。对照植株为2n=2x=58,未发现多核细胞。     

白扁豆的核型分析

白扁豆(Dolichos lablab)为蝶形花科一年生草本。关于白扁豆的染色体数目和核型研究,国内尚未见报道。我们的实验观察结果显示了白扁豆体细胞的染色体数目为2n=22。我们测量了7个根尖细胞中期染色体的平均值。白扁豆的核型公式为2n=2x=18m 4Sm。除     

杉木染色体的研究简报

笔者将武昌狮子山人工种植的杉木林的核型进行了观察。种子在25℃的温箱中发芽,取根尖用常规压片法制片。核型分析取7个细胞的平均值。观察结果如下:杉木体细胞具有22条染色体(2n=22),与前人报道一致。未发现B染色体。染色体的相对长度、臂比和类型见表1。染色体形态和模式图见图1—1和图2。     

杉木染色体的研究简报

笔者将武昌狮子山人工种植的杉木林的核型进行了观察。种子在25℃的温箱中发芽,取根尖用常规压片法制片。核型分析取7个细胞的平均值。观察结果如下:杉木体细胞具有22条染色体(2n=22),与前人报道一致。未发现B染色体。染色体的相对长度、臂比和类型见表1。染色体形态和模式图见图1—1和图2。     

Cytogenetic study of spontaneous lympholeukemia in AKR mice in the process of its transplantation to an isogeneic line of animals]

Spontaneous leucosis was cytogenetically studied in subsequent generations (from 1 to 150) of AKR mice. By means of the differential staining technique of chromosomes, large variations in chromosome numbers were found in the karyotypes of leucotic cells of different generations, and the formation of cell clones containing different marker chromosomes as well as the dominance of a hyperdiploid clone with 41-42 chromosomes was revealed. Chromosome analysis of such hyperdiploid cells of the 150th generation has indicated that the supernumerary chromosomes (in 88.0% of cases examined) belong to the smallest chromosomes of the mouse karyogramm (to the 18-19th chromosome pairs or to chromosomes smaller than those of 19th pair). Similar trisomy was also observed in hypodiploid and pseudodiploid leucosis cells. It is suggested that the cell clone with trisomy for the smallest chromosomes is specific to the spontaneous lympholeucosis in AKR mice as well as to the leucosis transplanted to isogenic mice for a number of subsequent generations. Increased rate of hyperdiploid cells was associated with a generalization of leucosis. It was concluded that the development rate and the severity of transplanted lympholeucosis in AKR mice was determined by the domination of the cell clone with trisomy for the 18-19th chromosome pairs in the population of leucotic cells.     

Recovering polyploid papaya in vitro regenerants as screened by flow cytometry

Several protocols have been proposed for in vitro propagation of papaya, either based on somatic embryogenesis or shoot organogenesis. It is well-known that tissue culture-based approaches are frequently associated with somaclonal variation. Whether on the one hand this phenomenon can preclude further stages of in vitro culture, on the other hand it can generate useful genetic variability for crop improvement. However, somaclonal variation analyses are limited in papaya tissue culture. The DNA ploidy level of 250 papaya somatic embryogenesis-derived plantlets from immature zygotic embryos was analyzed by flow cytometry. In vitro-grown and greenhouse seed-derived plantlets were used as diploid standards. Flow cytometry unambiguously evidenced euploid (diploid, mixoploid, triploid and tetraploid) and aneuploid papaya plantlets, indicating that in vitro culture conditions can lead the occurrence of somaclonal variation. Additionally, the two subsequent flow cytometry analyses showed that the DNA ploidy level remained stable in all cloned papaya plantlets during the successive subcultures in the multiplication medium.     

发根农杆菌对骆驼刺的转化及转化组织的形态发生

将骆驼刺离体再生苗的茎切段经发根农杆菌A4菌株感染后,在含500mg/L头孢霉素的MS无激素培养基上培养,产生了转化的发根和愈伤组织.转化根在附加2mg/L2,4-D和0.5-1mg/L6BA的MS培养基上培养后,亦可诱导出愈伤组织.在含3mg/L6BA和0.5mg/LNAA的培养基上诱导出了苗的分化.冠瘿碱分析表明,在95%以上的发根和75%的转化愈伤组织及再生植株中都显示了T-DNA的整合和表达.染色体检查发现,约81%的发根细胞具有正常染色体数(2n=18),其余则存在染色体数目的变化,在继代培养一年之后,转化体仍维持旺盛的再生能力.     

Agrobacterium rhizogenes-mediated transformation and the regeneration of transformants in Alhagi pseudalhagi]

The regenerated shoot segments of Alhagi pseudalhagi were sliced and infected with Agrobacterium rhizogenes strain A4. The hairy roots and transformed calli were obtained through selection on hormone free MS medium. The transformants were cultured on MS medium with 2 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) and 0.5-1 mg/L 6-benzylaminopurine (6-BA) to induce calli. 3 mg/L 6-BA and 0.5 mg/L naphthalene acetic acid (NAA) were applied for shoot differentiation. Shoots were planted on MS medium with 2 mg/L indole-3-butyric acid (IBA) and produced roots. Opine analysis proved the integration and expression of T-DNA in over 95% hairy roots, 75% transformed calli and transformed plantlets respectively. The 81% hairy root cells had normal chromosome numbers (2n = 18). The alterations of chromosome number were observed. After one year of subculturing, the regeneration ability of transformants was maintained.     

Study on the Hybrid Endosperm Culture of Wheat-Rye In Vitro

The endosperm culture of wheat-rye hybrid was studied in order to explore a new pathway of chromosome engineering. The preliminary results were obtained to show that the endosperm callus formation could be induced from the young endosperm within 7–14 days after crossing on the medium supplemented with 2 ppm 2,4-D, 0.5 ppm kinetin and 3%–8% sucrose. The induction frequency of callus amounts to 35.3%. When the calli were transfered onto an auxin step-down medium containing 0.5 ppm IAA and 1 ppm kinetin, both shoots and roots were formed. 4 endosperm plantlets were obtained. The chromosome number in somatic cells of endosperm plantlets was very unstable. The numbers varied from 6—42, but there is no 49 to be found. The chromosome number with 1—4 times of 7 can be found in higher percentage.     

Production of Doubled Haploids from Androgenic Embryoids and Plantlets of Tobacco

In four experiments, the chromosome doubling effect of acenaphthene vapour was tested on androgenic embryoids and/or plantlets of tobacco. The maximum rate of plants with doubled chromosome numbers (41.3 % diploids plus 2.7 % tetraploids) was recorded when approx. 100 mg acenaphthene in small and sterilized cheese-cloth bags were hanged for 72 h, into the culture jars (6.0 × 11.5 cm), containing 4 – 6 androgenic plantlets newly transferred from culture tubes. Acenaphthene treatments performed at the earlier stages of culture resulted in lower percentages (from 0.0 to 6.3 %). This revised version was published online in July 2006 with corrections to the Cover Date.     

甘蔗组织培养中染色体数目变异的初步研究

本文通过甘蔗桂糖11号组培腋芽苗与其原种的染色体数目的比较,研究了腋芽苗染色体数目的变化情况。发现腋芽苗82％的细胞的染色体数目仍在其原种染色体数目变异的高峰之内。     

Phenotypic Variation and Changes of Chromosome Number in Plantlets Regenerated from Potato Protoplasts

Morphological variation and change of chromosome number in the plantlets of potato (Solanum tuberosum L. cv. Xiao Yie Zi × Duo Zi Bai) regenerated from mesophyll protoplasts have been studied. The normal plantlets from protoplasts were similar to parent plants. Their chromosome numbers were 2n = 48±or 2n= 72 of euploid. The plantlets with distinctive phenotypic variation were likely to be aneuploid with increased chromosome numbers.     

连续多代UV-B照射对麦长管蚜保护酶活性的影响

【目的】为探明中波紫外线（UV-B）连续多代处理对麦长管蚜 Sitobion avenae (Fabricius ) 的作用机制,发现在UV-B环境压力下害虫进化动力。【方法】用强度为0.25 W/m²的UV-B对每代麦长管蚜进行6 h照射,以处理后成蚜当天产的仔蚜为继代饲养材料,连续饲养18代,提取第1,4,8,12,15和18代的对照组和处理组无翅孤雌成蚜的保护酶液,利用分光光度计测定其超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）3种保护酶活性。【结果】不同世代的对照组间3种保护酶活性均无差异（P>0.05）,处理组间有显著差异（P<0.05）。随着UV-B胁迫世代增加,SOD活性呈先升高后下降的趋势,活性高峰出现在第15 代。POD活性呈下降趋势,处理组活性均高于对照组,且在第1和4代处理组与对照组间差异极显著（P<0.01）。CAT活性先下降后升高,在第8, 12和15代处理组与对照组间无显著差异（P>0.05）,而至第18代处理组与对照组间差异又恢复为极显著（P<0.01）。【结论】麦长管蚜受到短期UV-B胁迫时,其体内SOD,POD和CAT 3种保护酶活性均升高,以抵御UV-B胁迫引起的自由基伤害;而经过到长期UV-B胁迫后,主要依靠SOD和CAT 2种保护酶清除活性氧自由基。     

四个酿酒葡萄品种组培快繁体系的初建

为了提高酿酒葡（Vitis vinifera）苗木繁殖速度及苗木品质,以‘赤霞珠’、‘西拉’、‘霞多丽’和‘美乐’4／p品种为试材,研究无菌外植体建立、启动培养、增殖培养和驯化移栽环节的关键技术,初步建立酿酒葡萄组培快繁体系。结果表明,以半木质化茎段为外植体接种成活率高,在培养基MS＋IBA0．2mg·L-1＋6．BA1．0mg·L-1＋KT0．5mg·L-1上启动培养外植体单芽萌发率最高,以培养基1／2MS＋IBA0．2mg·L-1＋KT1．0mg·L-1增殖培养兼生根诱导,组培苗生长健壮,繁殖率高。增殖培养6代后,‘赤霞珠’、‘西拉’、‘霞多丽’和‘美乐’分别由12株葡萄苗扩繁为l383株、1095株、744株和100株。组培苗驯化培养3周后移栽至营养钵,4个品种成活率均在72％以上。此组培快繁体系基本适用于4个酿酒葡萄品种,可应用于科学研究及工业化大规模生产。