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1.
Summary Chromosome variation was studied in bulk populations of 27 advanced strains of hexaploid Triticale. Average frequency of euploids (2n=42) in the 27 strains analyzed was 81.5% with a range from 57.2% to 100.0%. Three strains showed particularly high aneuploid frequency in the bulk population; the average frequency for the three strains was 39.0%, while the mean for the other 24 strains was 14.8%. The progenies of 42-chromosome plants derived from the aforementioned three strains had 89.4% euploids on an average. It is assumed that a monosomic plant was selected in a single-plant (or spike) selection during the breeding period. The frequency of aneuploids is very high, even after several generations of breeding. Routine chromosome checking is recommended in breeding Triticale and other cytologically unstable induced amphiploids.Contribution No. 175 of the Department of Plant Science, University of Manitoba, Winnipeg, Canada. 相似文献
2.
Summary To examine whether chromosome numbers of Brassicoraphanus (amphidiploids between Brassica japonica
Sieb. and Raphanus sativus L.) are stable or not, the following four items were studied with some plants during the 2nd–11th generations: (1) chromosome numbers of open-pollinated progenies from eu-, hyper-, and hypoploids, (2) chromosome distribution at metaphase II in these plants, (3) frequency of euploids in relation to flower colour and generation, (4) seed fertility in eu-and aneuploids in relation to flower colour. In early generations, hyper-and hypoploids were frequently produced from euploids. In later generations, however, the chromosome number became less unstable. In euploids (2n=38), chromosome numbers at metaphase II showed some variation, and the mean frequency of the euploid chromosome number (n=19) was approximately 78%. This value was almost the same in white-and yellow-flowered plants through early and late generations. Nevertheless, yellow-flowered plants tended to produce euploids more frequently than did white-flowered ones. It is assumed that the difference in euploid productivity between yellow-and white-flowered plants is due to the difference in seed fertility between them. The progeny of each hypoploid showed higher chromosome numbers than their parents. The progeny of each hyperploid showed lower chromosome numbers than their parents: they were approaching to euploidy. This phenomenon, together with higher fertility of euploids and lower fertility of aneuploids, will favor the maintenance of euploidy of this strain. 相似文献
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4.
M. Gul Hossain 《Euphytica》1978,27(1):137-143
Summary Aneuploidy was studied in populations selected for high seed-set with regular meiosis and low-seedset with irregular meiosis and an unselected population of the same origin. The frequency of aneuploids was significantly reduced in the high population that was characterised by increased bivalent frequency. In spite of a similar quadrivalent frequency in euploid plants of the low and the unselected population, the former population had a significantly higher frequency of aneuploids. However, there was no significant difference in the performance of aneuploid plants from the three populations. The results indicated that hyperaneuploid gametes were less functional than hypoaneuploid gametes but no significant difference was found in the performance of hypo- and hyperancuploids. 相似文献
5.
R. J. Hecker 《Euphytica》1972,21(1):106-111
Summary The effect of inbreeding on vegetative vigor, as measured by root yield, was evaluated in two diploid (2x) and equivalent autotetraploid (4x) sugarbeet strains, and one additional 2x and one 4x strain. Root yields of the 2x and 4x S1 progenies each averaged 86.7% of their comparable open-pollinated progeny. Inbreeding depression of root yield was variable from strain to strain. The selfed 4x populations, when compared with their 2x equivalents, suffered more yield depression than was expected on the basis of the theoretic approach to homozygosity associated with selfing in autotetraploids. The inbreeding depression was partly attributed to (a) the approach to homozygosity, and (b) the fact that partially homozygous 4x S1 individuals were probably unable to make compensating growth when located adjacent to a low vigor aneuploid plant. A major part of root yield depression remained unexplained. Sucrose content within strains and within ploidy levels was not significantly affected by one generation of selfing.Joint contribution of the Crops Research Division, Agricultural Research Service, US Department of Agriculture, the Colorado Agricultural Experiment Station, and the Beet Sugar Development Foundation. Published with the approval of the Director of the Colorado Agricultural Experiment Station as Scientific Series No. 1582. 相似文献
6.
采用种子萌发及盆栽试验测定菌株Thhyl对番茄的促生长作用。结果表明：菌株培养液浓度在40％以下对番茄种子萌发具有强的促生作用,大于40％时对番茄种子萌发具有抑制作用;菌株培养液比菌株胞外分泌物对种子的萌发促生作用好;菌株Thhyl培养液对幼苗平均鲜重和干重增长率均达到120％以上;对幼苗的平均株高增长62．01％;对幼苗的平均根长增长率为44．14％;对幼苗的平均茎粗增长率为50．00％。以抗利福平（300μg／mL）的拮抗病原茵双抗性为标准,测定菌株Thhyl的内生及定殖性。采用浸种和叶片涂抹2种方法,结果证明菌株Thhyl能在番茄体内定殖,其中叶片涂抹法在植株体内的定殖量较浸种处理多。 相似文献
7.
江汉平原大豆品系表型分析及综合评价 总被引：1，自引：0，他引：1
种质资源是大豆育种的基础,理论方法是品种选育的关键。以64份大豆品系为材料,采用变异性分析、相关性分析、因子分析和聚类分析等多元分析方法相结合,对大豆品系的10个农艺性状及产量性状进行研究,筛选适宜江汉平原种植的大豆品系,同时探究影响大豆产量的关键因素,为选育优质高产大豆品种提供种质和理论依据。结果表明,大豆品系10个农艺性状的变异系数为4.19%~46.95%,有效分枝数变异系数最大,蛋白质含量变异系数最小;因子分析将10个农艺性状转化为4个主因子,分别为产量构成因子、株高因子、粒重因子和品质因子,累计贡献率为80.067%。由农艺性状与综合得分相关性分析可知,生育期、株高、主茎节数、单株荚数、单株粒数、单株粒重和蛋白质含量7个农艺性状可作为大豆品系综合评价指标。聚类分析将64份大豆品系分成3个类群,类群Ⅰ31份,类群Ⅱ24份,类群Ⅲ 9份,类群Ⅲ大豆品系综合表现较好,适宜在江汉平原种植。 相似文献
8.
湖北、江苏团头鲂源嗜水气单胞菌致病性与药敏特性研究 总被引：2，自引：1，他引：1
对湖北、江苏两省的8个团头鲂主养区分离的嗜水气单胞菌的致病性和药敏特性进行比较,分析不同地区嗜水气单胞菌在致病力和耐药性方面的差异。结果表明：气溶素基因(aer)、丝氨酸蛋白酶基因(ahp)、溶血素基因(hly)、抗金属蛋白酶基因(ast)、肠毒素基因(alt)在各菌株中的携带率分别为100%(8/8)、75%(6/8)、87.5%(7/8)、100%(8/8)、75%(6/8),仅E6、X22分别缺少ahp、alt基因和ahp、hly、alt基因;6株均携带上述5个毒力基因的菌株,其中有5株菌的溶血价和溶蛋白效价均达到最高的1:128,W25为1:128、1:64,E6和X22分别是1:64和1:64、1:32和1:64;上述6株菌的LD50值在5.0×105~1.0×106 cfu/mL之间,E6和X22的LD50值分别为2.4×106 cfu/mL和4.0×106 cfu/mL;不同地区的嗜水气单胞菌对孢头菌素类、氟苯尼考高度敏感,对青霉素类高度不敏感,对氨基糖苷类、磺胺类呈现一定程度的耐药性;江苏省分离菌株对恩诺沙星、四环素的耐药性明显高于湖北省的分离株,而湖北省分离株对新生霉素的耐药性要高于江苏省的分离菌株。可以得出,不同地区的菌株致病力没有显著差异,而在耐药性方面呈现一定的区域差异性。 相似文献
9.
库存玉米种质资源发芽力监测与分析 总被引：1，自引：1，他引：0
为给种质库贮藏玉米种质及其他作物种质发芽力监测、方法制定及安全保存期限的确定提供科学依据。对种质库中8种不同入库编号1729份的玉米种质资源取样进行发芽势和发芽率监测并将结果与入库前的发芽数据进行比较分析。结果表明,贮藏27~32 年后,种子平均发芽势为82.66%,平均发芽率为88.09%,有86.58%以上的种子发芽率仍保持在75%以上,但有73 份种子发芽率已降至50%以下;贮藏31~32 年的种质发芽率下降明显,而贮藏27~30 年的种质平均发芽率下降不明显。不同原产地的玉米种质经31 年长期贮藏后发芽率下降不同,原产广西地区种质比原产区外、国外引种种质发芽率高。不同年份贮藏的玉米种质资源或同一年份贮藏的不同原产地的玉米种质资源经低温长期保存后发芽力下降趋势不同,玉米种质资源长期库的安全保存期限可达30年以上。 相似文献
10.
K. J. Frey 《Euphytica》1967,16(3):341-349
Heterogeneous and segregating oat populations subjected to no selection and to mass selection for seed width for five consecutive generations were evaluated for 100-seed weight, heading date and plant height.The mass-selection technique, which consisted of passing the seeds over a screen with 12.7×2.4 mm slots and propagating the seeds too wide to go through the slots, was repeated for five consecutive generations (F3 through F7). Comparable unselected populations were grown each year. Remnant seeds from each check and mass-selected population were stored for future studies.In 1963, 500 random seeds from each of the six unselected populations (F2 through F7), from each of the five mass-selected populations (F3 through F7) and from a pure line were space-planted in the field. In 1964, the progenies from 75 random strains (a strain was the progeny of one spaced plant) from each of the 12 populations were sown in a randomized-block experiment with three replicates. In 1966, the strains from the last (F7) generation of the unselected and mass-selected lines of descent (75 strains from each) were tested for yield in a 7-replicate randomized block experiment.The mass-selection technique increased the mean 100-seed weight, whereas in the unselected line of descent, the mean 100-seed weight did not change. The mean heading dates became later and the mean plant heights taller with the mass-selection procedure. The mean yield of the final mass-selection population was nine percent higher than that of the comparable unselected population.In spite of the associated changes between 100-seed weight and plant height and heading date in successive generations; the genotypic correlations among strains within populations indicated that these three traits were inherited independently. In advanced generations (F6 and F7), the genotypic variances for heading date and 100-seed weight were reduced in both the unselected and mass-selected lines of descent, whereas, for plant height no significant change occurred in either.Journal No. J-5586 of the Iowa Agricultural and Home Economics Experiment Station, Ames, Iowa, Project 1176. In cooperation with the Crops Research Division, Agricultural Research Service. U.S. Department of Agriculture.Professor of Plant Breeding. 相似文献
11.
辅助营养源对蜜环菌栽培种的影响 总被引：1，自引：1，他引：0
以昭通本地的一株优良蜜环菌SNA04为研究对象,在蜜环菌栽培种制作过程中添加一定量的不同辅助营养物质以考察辅助营养物质对蜜环菌菌株生长的影响,为实现昭通本地蜜环菌的快速工业化制种及大规模生产奠定基础。用SNA04作菌种,栎树枝条作主要培养基,不同浓度梯度的葡萄糖、乙醇、酵母膏、蛋白胨和土豆汁作辅助营养源培养蜜环菌栽培种。与对照相比,加入辅助营养源后,菌索生长速度提高,菌株生长状况得到改良,表现为菌索长势旺、分枝多、色白、粗壮等。其中,菌索在加有250 g/L土豆汁菌种瓶中长势最强,平均生长速度达到了1.29 cm/天,比对照中的菌索生长速度快0.48 cm/天。所添加的5种营养液培养基中,最适合菌索生长的是加有土豆汁的菌枝培养基。土豆是昭通地区主产作物,具有较高产量,可以将其作为蜜环菌栽培种的辅助营养源加以利用。 相似文献
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13.
Summary Crosses between Fragaria moschata (2n=42) and Potentilla fruticosa (2n=14) produced many seeds; about half of these germinated, but only nine plants were obtained from 554 seedlings. Five plants died without flowering, and four were vigorous but sterile. Four plants had the expected chromosome number (2n=28), one plant had 21 chromosomes, and four were aneuploid with 23, 24, 25 and 27 chromosomes respectively. Response to growth substances giving elongated stem internodes and swollen but not succulent receptacles provided evidence that two of the plant were hybrids. It is suggested that all nine plants originated from a normal fertilisation which was followed in some cases by chromosome elimination at an early stage of embryo development. 相似文献
14.
Fifty grass pea land race populations of Ethiopia that were selected based on administrative regions and different altitude
classes were used in this study to determine variability in morphological characters, Oxalyl Diamino Propanoic acid(ODAP)
– a causative agent of lathyrism, and protein contents and their associations. Highly significant differences were observed
among the populations for most of the morphological characters. Populations collected from Gondar region and the higher altitude
group (>2550 m) showed the highest mean and coefficient of variation indicating the presence of high genetic diversity in
this region and altitude group. ODAP analysis from single plants showed significant variation both within a population and
between populations. Four individual plants with low ODAP contents ranging from 0.149% to 0.182% (range within safe level)
were identified in populations collected from different regions, indicating the diversity and variation of this trait with
in one population and between regions. These low ODAP lines are considered important for further breeding. The association
of ODAP with grain yield, biomass, plant height and seed size was negative, suggesting that the selection of tall and late
maturing varieties with large seed size and high grain yield potential will enable the development of varieties with low ODAP
content.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
15.
对采收的紫果型黑蕊猕猴桃(Actinidia melanandra)种子进行了不同温度、不同层积时间和不同浓度赤霉素处理的发芽试验,结果表明,不同温度的种子发芽率有极显著差异(p<0.01),多重比较显示平均发芽率结果为23℃>18℃>28℃>13℃,23℃的发芽率为72.67%。不同层积时间的种子发芽率有极显著差异(p<0.01),多重比较显示发芽率60 d>45 d>75 d>30 d>0,层积60 d的平均发芽率为79.67%。不同浓度赤霉素处理的种子发芽率有极显著差异(p<0.01),多重比较显示发芽率600 mg·L^-1>900 mg·L^-1>300 mg·L^-1>0,600 mg·L^-1的发芽率最高,为14%。紫果型黑蕊猕猴桃种子最佳萌发条件为:温度23℃,低温层积60 d,600 mg·L^-1的赤霉素浸泡种子。 相似文献
16.
以黄瓜（Cucumis sativus L.）子叶节为外植体，研究了品种、6-苄氨基嘌呤、外植体大小及硝酸银对黄瓜直接不定芽诱导的影响。结果表明：不同黄瓜品种直接不定芽数量诱导存在显著差异，但长度诱导无显著差异；6-苄氨基嘌呤对直接不定芽数量和长度的诱导作用显著，其中4.0mg/L为数量诱导适宜浓度，其出芽率和每外植体出芽数达到最高，分别为100.0%和11.1，0.5mg/L为长度诱导适宜浓度，其平均芽长12.0mm；外植体的大小对直接不定芽数量和长度均具显著影响，随着子叶的增大诱导直接不定芽的数量和长度增加，其中单片完整子叶为最适宜大小，其出芽率、每外植体出芽数和平均芽长分别达到100%、6.7和17.1mm；硝酸银也对直接不定芽数量诱导影响显著，其中2.0mg/L为适宜浓度，出芽率和每外植体出芽数分别达到97.2%和4.2，但对芽长有抑制作用。 相似文献
17.
B. S. Ahloowalia 《Euphytica》1982,31(1):103-111
Summary Aneuploid plants of perennial ryegrass (Lolium perenne L.) with 2n=15 to 30 chromosomes were obtained by crossing a near-triploid (2n=3x+1=22) with a diploid or on open-pollination with diploids and tetraploids. Aneuploids occurred with a frequency of 83% in near triploid × diploid progeny and 92% on open-pollination with diploid and tetraploid plants. Aneuploid plants with 15 to 18 chromosomes resembled diploids in morphology and those with 19 to 30 chromosomes were akin to tetraploids. Meiotic studies suggested that most aneuploid plants resulted from transmission of aneuploid egg cells (n=8 to 23). Aneuploid plants with 2n=27 to 30 chromosomes in the progeny of 22×14 cross originated from unreduced egg cells. Plants with 19 to 21 chromosomes were recovered only by immature seed culture. Aneuploid plants with 26 to 30 chromosomes and triploids (2n=21) had higher pollen fertility and bigger seeds than plants with 15 to 22 chromosomes. 相似文献
18.
Karyotypic and electrophoretic studies on taro and its origin 总被引：4，自引：0，他引：4
Summary Karyotypes and electrophoretic pattern of 15 strains of taro were studied. Strains collected from the northeast India hill state, Meghalaya were diploids and triploids whereas those from the plains of south India were diploids and of north India was a triploid. The diploids had 2n=28 and triploids showed 2n=42 chromosomes. The wild taro had the most asymmetrical karyotype. The protein content varied from 4.2 to 11.4 mg/g dry wt. The maximum protein content was found in a triploid strain 8 (11.4 mg/g dry wt) and minimum in the wild taro (4.2 mg/g dry wt). The number of protein bands was 7 in the wild taro (diploid) and 12 in one of the cultivated triploid strain. Meghalaya strains showed great variation with respect to leaf size and tuber shape and size. All the strains have diverged at morphological, karyotypic and genotypic levels. It is suggested that taro might have originated in the north-eastern India. 相似文献
19.
为探索AM真菌在牡丹组培上的应用效益及机理,保存和扩繁新优杂交牡丹资源及提供解决牡丹组培中生根难、移栽成活率低等瓶颈问题的新途径,选用牡丹新优杂交系种子进行胚培养得到胚根苗无菌体系,在瓶内对胚根苗接种AM真菌获得菌根化组培苗,继而研究AM真菌对牡丹组培苗生长发育和矿质元素吸收的影响.结果 表明,AM真菌能显著促进牡丹组... 相似文献
20.
杭州地区黄瓜猝倒病菌产嗜铁素拮抗菌的筛选与评价 总被引：1，自引：1，他引：1
从杭州地区各蔬菜种植地大量采集土样，采用平板稀释法从中分离纯化得到789个细菌分离物。室内平板对峙法获得对黄瓜猝倒病菌有明显拮抗作用的菌株21个，所占比例为2.67%，其抑菌圈直径为3.1~16.4 mm。再利用选择性培养基法从中筛选得到9株嗜铁素产生菌。最后对黄瓜猝倒病菌产嗜铁素拮抗菌进行评价，结果表明，各菌株产生嗜铁素的能力不同，定性与定量分析结果基本吻合；嗜铁素光吸收特性研究表明，pH直接影响嗜铁素光吸收，过酸过碱的条件光吸收峰偏向短波长，而中性条件下光吸收峰偏向长波长。pH8.3有3个吸收峰，分别在224.0 nm，264.0 nm和400.0 nm附近，并且光吸收峰最大，说明pH8.3较适合试验菌产嗜铁素；嗜铁素产生菌对黄瓜生长的初步研究表明，其对黄瓜生长有3种作用即：促进、抑制和影响不大。 相似文献