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1.
杂交稻野败胞质对稻瘟病菌、白叶枯病菌感病性的研究 总被引：9，自引：0，他引：9
选用3个水稻野败胞质不育系及相应的保持系,3个恢复系及它们相应的野败胞质代换系,这些不育系、保持系同恢复系配组的18个 F_1,分别在秧苗期接种属我国7个稻瘟病生理小种群的21个菌株;在成株期接种15个白叶枯病菌株。结果表明,野败胞质较之正常胞质表现对这两种病菌感病稍轻;这种差异在多数保持系的基因型背景下达到显著水准, 相似文献
2.
高粱出苗能力的遗传研究 总被引：2，自引：0，他引：2
本文利用4个不育系和4个恢复系、两组亲本及其16个杂种、两个杂交组合的F_2为材料研究了高粱胚轴伸长潜力、出苗日数和出苗率的遗传规律及其相互关系.结果表明,高粱胚轴伸长潜力和出苗日数具有较高的遗传力,其基因系统的加性效应占主导地位;品种胚轴伸长潜力大小是出苗率高低的决定因素;出苗日数与胚轴伸长潜力呈高度负相关. 相似文献
3.
利用2个K型不育系与不同K型恢复系组配测交组合，研究了不同不育系的易恢性及其遗传机理，恢复系在年份间恢复度的稳定性以及播期、播量对育性恢复度的影响。结果表明, 2个K型不育系易恢性有明显差异，其易恢性受2对主基因和微效多基因共同控制，不育系易恢性与恢复系恢复力差异的机理是相同的。大多数K型杂交组合的恢复度在不同年份间有较大差异，但恢复度高的组合稳定性较好，异常年份鉴定恢复系的恢复力是最有效的。播期对恢复度的影响较大，播量影响较小。抽穗至开花期间的异常高温是恢复度不稳定的主要外部原因。 相似文献
4.
中国高粱地方品种遗传多样性评价及中、外高粱遗传变异水平比较 总被引：2，自引：0，他引：2
利用32个高粱(Sorghum bicolor L.)核基因组多态性SSR(simple sequence repeats)位点,以69份国外品种为对照,对12个地区的184份中国高粱地方品种进行了遗传多样性分析。研究结果表明,中国高粱的遗传多样性明显低于国外高粱。中国高粱和国外高粱的等位基因丰度(Rs)和基因多样性(He)分别为9.81、0.629和11.52、0.745。中国高粱的遗传多样性明显低于东非(He=0.732)、北美(He=0.707)和南亚(He=0.712)高粱,与南非高粱相当(He=0.609)。不同地区中国高粱地方品种遗传变异水平存在明显差异,12个地区高粱种质等位基因丰度在3.64~4.88之间,基因多样性值在0.517~0.714之间。吉林高粱地方品种遗传变异最为丰富(He=0.714),与北美、南亚高粱相当。中国高粱与国外高粱之间遗传分化明显,而中国高粱地方品种地区间和类型间分化极弱。主成分分析(PCA)能够明显区分中外高粱种质但不能将中国高粱按地区或类型分开。分子方差分析(AMOVA)表明,中外高粱间的遗传变异占全部参试材料遗传变异的20.43%。中国高粱遗传变异主要存在于地区内材料间(占总变异91.94%)或生态区内材料间(占总变异94.97%)。在品种类型方面,中国高粱绝大部分遗传变异存在于穗型内材料间(占总变异97.93%)。本研究支持中国高粱外来说的观点。 相似文献
5.
The primitive, upland cotton landrace collection represents one of the untapped genetic resources in cotton breeding programs. Efforts to utilize these resources have been slow, but the development of day-neutral converted germplasm lines offers tremendous potential for broadening the genetic base in upland cotton. Using topcross hybrids involving elite germplasm from the unique Pee Dee germplasm enhancement program, we evaluated the breeding potential of a select number of day-neutral converted racestocks. The mean performance of parental lines and F2 topcross hybrids along with genetic effect estimates indicate that day-neutral converted germplasm lines decreased agronomic performance while increasing fiber quality performance. Results suggest that crosses between day-neutral converted racestocks and elite Pee Dee germplasm lines result in new allelic combinations associated with improved fiber quality performance that interact in a non-additive way. However, it appears that converted racestocks transmit negatively correlated alleles for agronomic performance and fiber quality. These negatively correlated allelic combinations present a major challenge for cotton breeding programs. Future efforts that incorporate DNA based selection methods to identify and fix introgressed segments from converted racestocks and their offspring should enhance the use of the genetic variation present in the primitive racestock germplasm accessions. 相似文献
6.
2006-2007年广西杂交稻区试回顾及发展商榷 总被引：3，自引：0，他引：3
回顾了广西杂交水稻区试历程,通过对2006、2007年广西杂交稻区试结果进行具体分析,肯定成绩,发现问题,并提出对今后发展方向的建议。2年来的区试结果表明,广西杂交水稻区试的参试组合类型配套齐全丰富,在选育组合数量,产量水平及稻米品质方面取得较大进步。但是存在着一些影响育种突破的重要问题。首先,参试组合很难在抗病虫上有所突破。其次,参试组合的综合性状有待进一步提高。今后,杂交水稻育种应扩大遗传基础,加大籼粳稻种质的遗传利用,加强野生稻优异种质的利用,把抗性育种放到主要议事日程,进一步促进杂交水稻综合性状的改良与协调,向超高产稻方向发展。 相似文献
7.
我国主要高粱杂交种的系谱分析 总被引：5，自引：0，他引：5
<正> 我国推广高粱杂交种已有廿余年的历史。现在剖析一下主要杂交种及其亲本的系谱,对确定今后选育的策略及方法不无裨益。我们依据《杂交高粱—选育—制种—栽培》和《优良杂交高粱组合及亲本》两书中提供的和近期可能收集到的资料,分析中国主要高粱杂交种及其亲本的系谱,并讨论有关的遗传基础宽度问题。 相似文献
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新引进高粱雄性不育系的配合力分析 总被引：9，自引：0，他引：9
按格子方法对新引进美国高梁不育系 Tx622A、Tx623A、Tx624A 等进行了主要农艺性状的配合力分析。不育系间穗粒重、穗粒数、生育期、株高、穗长、角质含量配合力差异显著,千粒重配合力差异不显著。在全部被研究性状的遗传控制中,加性基因效应占主导。除 Tx622A 外,其余新引不育系穗粒重,穗粒数的一般配合力效应优于3197A,全部 相似文献
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中国糯玉米wx基因种质资源遗传多样性 总被引：7，自引：1，他引：7
Waxy(Wx)基因是众多作物导致糯性突变的关键基因,在玉米作物群体内深入研究Wx基因对中国糯玉米品质育种和种质创新具有重要意义。本研究利用325份(309份来自中国,11份来自泰国和5份来自韩国)糯玉米种质材料做了wx基因突变类型的调查和表观直链淀粉含量(AAC)测定。结果表明, 中国糯玉米的wx基因的遗传多样性很低,主要存在wx-D7和wx-D10两种突变类型,占96.9%;中国北方及韩国的糯玉米wx基因突变类型都是wx-D7类型,南方及泰国糯玉米wx基因突变类型都是wx-D10类型;糯玉米地方品种的wx基因型以wx-D10为主,占78.9%,而商业杂交种和自交系的wx基因型以wx-D7为主,分别占88.7%和86.6%。分析表明,中国糯玉米商业杂交种和自交系的AAC均值较低(小于2.2%)且无显著差异,但地方品种的AAC均值较高;wx-D7基因型糯玉米的AAC均值低且变化幅度较小,而wx-D10基因型糯玉米的AAC均值最高且变化幅度较大。本文还讨论了中国糯玉米主要wx基因型的地理分布、起源以及其他的wx基因突变类型。 相似文献
12.
Merja Veteläinen 《Euphytica》1994,79(1-2):127-136
Summary Utilization of exotic germplasm offers an approach to broaden genetic variability in breeding populations. This study was conducted in order to 1) compare germplasm of exotic origin with adapted Swedish barleys with respect to genetic differences and 2) to evaluate how exotic material affected agronomic performance in complex crosses. Allozyme studies showed the following Nei's gene diversities among parents: 0.13 (adapted parents), 0.16 (landraces) and 0.25 (H. spontaneum). Cluster analysis indicated that parental groups were genetically divergent. Earliness, straw length, number of ears per plant and thousand kernel weight (TKW) were studied. Variation in agronomic traits showed the following pattern: landraces > H. spontaneum > adapted lines. The best sources for earliness were adapted parents and landraces. Mean straw length was greatest in H. spontaneum lines. Number of ears per plant was quite similar in all groups. The highest TKW was among landraces and adapted parents. Hybrids from the complex crossing programme exceeded parents in earliness and TKW. An index composed from the four traits showed the most favorable frequency distributions for adapted parents and hybrids. Both genetic and agronomic studies indicate that new valuable variation from exotic germplasm may be introduced into barley breeding material. 相似文献
13.
Morag E. Ferguson Larry D. Robertson Brian V. Ford-Lloyd H. John Newbury Nigel Maxted 《Euphytica》1998,102(2):265-273
Lentil landraces from South Asia exhibit a low diversity and discordance with landraces from other countries according to
a combination of qualitative and quantitative agromorphological characters. They exhibit specific phenological adaptation
to the South Asian environment which precludes the direct use of alien germplasm in breeding programs in South Asia. An understanding
of the genetic relationships and diversity of South Asian lentil landraces, in relation to landraces from other countries,
is important in attempting to widen the genetic base of germplasm in the region. The objectives of this study were to investigate
the genetic relationships between lentil landraces from 3 South Asian countries (India, Nepal and Pakistan) and those from
13 other countries and to determine their relative genetic diversities, using both isozyme electrophoresis and random amplified
polymorphic DNA (RAPD) analysis. Polymorphisms were observed for 7 isozyme loci (16 alleles) and 22 RAPD loci. According to
Nei's genetic distance, germplasm from Afghanistan clustered with that from the South Asian countries. The germplasm from
these countries was striking different to that from the other countries studied. Based on genetic distance estimates from
RAPD analysis, the countries with the lowest diversity were Pakistan, Afghanistan and Nepal. These data support evidence at
the morphological level of a genetic bottleneck in lentil landraces from South Asia. Genetic relationships between countries
outside the South Asian group are discussed. Classification into macrosperma and microsperma types did not reflect overall
country relationships.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
San -San-Yi S. A. Jatoi T. Fujimura S. Yamanaka J. Watanabe K. N. Watanabe 《Plant Breeding》2008,127(2):189-196
We report the genetic diversity of tomato landraces from Myanmar, with reference to worldwide tomato accessions. Ten simple sequence repeat markers were screened and used to create diversity profiles of tomato germplasm. A total of 133 alleles were amplified from the germplasm investigated; alleles specific to landraces from Myanmar were also observed. Higher genetic diversity for the Myanmar landraces highlighted the broad genetic base of tomato germplasm. Principal component analysis showed that most of the Myanmar landraces were divergent from other accessions. The different approaches used to analyse landrace diversity documented the broader genetic base of germplasm from Myanmar, which is a non‐center of origin for tomato. Genetic diversity in the landraces may be attributable to diverse production systems used by different ethnic groups in Myanmar, ranging from natural hydroponics in eastern areas, to slash‐and‐burn fields in mountain areas and shifting cultivation in many parts of the country. The availability of uniform and high‐yielding cultivars/hybrids threatens the valuable landraces in Myanmar. We emphasize the need to evaluate tomato germplasm from Myanmar for different traits and sustainable use with simultaneous conservation. 相似文献
15.
元阳白脚老粳水稻地方品种内遗传异质性及意义 总被引：3，自引：1，他引：3
云南部分水稻(Oryza sativa L.)地方品种栽培历史悠久,是种质资源有效保护、可持续发展研究的极佳材料.本研究对一个栽种历史悠久的水稻地方品种的内部遗传异质性进行了微卫星(SSR)分析.采用24对引物对来自元阳新街镇4个寨子的40份白脚老粳品种以及5份对照品种进行了遗传背景分析,共检测出114个等位基因,其中在40份白脚老粳地方品种中检测到98个等位基因.UPGMA法构建的系统树显示,45份水稻品种遗传相似系数在0.413～1.000之间,而40份白脚老粳地方品种遗传相似系数在0.762～1.000之间,该品种的遗传多样性并非均匀地按地理位置分布,大新寨白脚老粳地方品种遗传丰度最高,小水井的遗传丰度最低.研究表明,相同地方品种不同村寨的居群遗传多样性不同,当地农民通过村寨之间的交换维系地方品种的永续发展. 相似文献
16.
M. E. Cisneros-López L. E. Mendoza-Onofre H. A. Zavaleta-Mancera V. A. González-Hernández L. Córdova-Téllez M. Hernández-Martínez & G. Mora-Aguilera 《Journal of Agronomy and Crop Science》2009,195(6):464-471
In A-lines of sorghum ( Sorghum bicolor L. Moench), seed production under field conditions with manual pollination is generally lower than that in self-pollinated B-lines. This may be associated with floral differences. Six pairs of A/B-lines and four R-lines were evaluated during 2005 and 2006 at Montecillo, State of México (2240 m altitude). Rachis length, number of primary branches and fertile flowers per panicle, 100-seed weight, seed number, seed yield and seed set per panicle were evaluated. In the A-lines, the pistil characteristics were also measured and in the male-fertile lines, the size of anthers and the amount and size of viable pollen were recorded. Compared with the A- and B-lines, the R-lines exhibited significantly higher (P ≤ 0.05) numbers of flowers, seed set and seed yield per panicle and they also produced more pollen grains of larger size and with greater viability during their longer flowering period (FP). Between A- and B-lines, there were differences (P ≤ 0.05) in most of the yield traits, which also interacted with year. The proportion of viable pollen in B- and R-lines (75 %) was not considered to be a factor that might account for their low seed production. Chilling temperatures (3.5–8.4 °C) during the FP could have affected stigma receptivity in the three different line types and thus may have reduced seed set in the male-fertile lines. 相似文献
17.
Commercial viability of three cytoplasmic-nuclear male sterility (CMS) systems (A4, A5 and Av) as potential alternatives to the most widely used A1 system in pearl millet (Pennisetum glaucum (L.) R.Br.) was evaluated in terms of stability of complete male sterility of four isonuclear A-lines (81A1, 81A4, 81A5 and 81Av) and the level and stability of male fertility restoration of their 44 single-cross hybrids. Lines 81A4 and 81A5 had no pollen shedders (PS), and there were very low frequency of non-PS plants of these A-lines that had a maximum of 1–5%
selfed seedset (SSS). In 81A1 and 81Av,there were, albeit low frequency (<1%) of PS plants, and relatively higher frequency of the non-PS plants in these two lines,
the more so in 81Av,had 1–5% and even greater SSS. Some hybrids made on each of the three A-lines (81A1, 81A4 and 81Av) had high and stable male fertility, while others made on the same three A-lines displayed large variation in SSS across
the environments, the more so in case of hybrids made on 81Av. These results indicate that the A4 CMS system provides a better alternative to the A1 CMS system, while the Av system does not. On the basis of highly stable male sterility and the highest frequency of pollinators behaving as maintainers,
the A5 CMS system appeared to be the best for A-line breeding. The commercial viability of this CMS system in breeding R-lines of
grain hybrids, however, still remains to be ascertained as no hybrid on it was fully male fertile in any environment.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
18.
Heterotic patterns in rapeseed (Brassica napus L.): II. Crosses between European winter and Chinese semi-winter lines 总被引：1，自引：0，他引：1
Chinese semi-winter rapeseed is genetically diverse from European winter rapeseed. Our objectives were (1) to evaluate the potential of semi-winter rapeseed for winter rapeseed hybrid breeding, (2) to assess the relative importance of general combining ability (GCA) vs. specific combining ability (SCA) among combinations between Chinese semi-winter and European winter rapeseed, and (3) to compare the strategies to predict heterosis based on parental genetic distance (GD) estimated from AFLP marker data and GCA for hybrid performance. Four winter male sterile lines from Germany as testers were crossed with 14 Chinese semi-winter rapeseed lines to develop 56 hybrids, which were evaluated together with their parents and commercial hybrids for seed yield, oil content and protein content under three environments in Germany. The Chinese parental lines were not adapted to local environmental conditions as demonstrated by lacking winter hardiness and poor seed yields per se . However, the hybrids between the Chinese parents and the adapted winter rapeseed lines exhibited high heterosis for seed yield. About 20% of the hybrids were significantly superior to the respective hybrid control under three environments. Additive gene effects mainly contributed to hybrid performance since the variance components of GCA were higher as compared with SCA. The correlation between parental GD and hybrid performance was found to be low whereas the correlation between GCA and hybrid performance was high and significant, with correlation coefficients of 0.95 for seed yield, 0.87 for oil content, and 0.91 for protein content, indicating that GCA can predict hybrid performance. These results demonstrate that Chinese semi-winter rapeseed germplasm has a great potential to increase seed yield in winter rapeseed hybrid breeding programmes in Europe. 相似文献
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种质资源狭窄和杂种优势单一,是制约我国玉米产业发展的重要因素之一。拓宽玉米种质基础,培育突破性育种新材料是选育优良玉米杂交种的基础与前提。热带、亚热带种质已经被证明具有较温带种质丰富的遗传多样性,其引入、改良和应用对丰富我国玉米种质多样性具有十分重要的意义。本研究以28份温热玉米自交系、4份Suwan群体来源自交系(QR 273、ZHL 908、T 32和QB 48)作母本,来自Iodent、Reid、PB、Lancaster和塘四平头类群的8个温带玉米自交系作父本的杂交后代为材料,2015年分别在河南郑州和河南华县对28份自交系和32个杂交组合进行农艺性状评价。结果显示,Suwan×Iodent杂交组合的株型、生育期、感光性等与温带地区杂交种相近;而Suwan自交系与其他类群自交系的杂交组合则表现出植株繁茂、抗倒性差、感光性强和生育期太晚等问题。利用Iodent种质早熟、马齿的特性能够有效改良Suwan种质生育期晚、光周期敏感的不足,获得较高的配合力。 相似文献