水稻白叶枯病抗性遗传力配合力的初步分析

 1978-1981年用12个品种(系)、共30个组合,其中包括国际公认的抗性品种IR₂₆、IR₃₆,观察这些代表品种杂交后代对白叶枯病抗性的遗传力和配合力。结果指出:(1)抗性的广义遗传力较高,相对遗传进度进展较快,表明抗性可早代选择;(2)抗性的一般配合力方差达极显著水准,且GCA:SCA的比值较高,显示加性基因占优势;(3)亲本一般配合力效应方向明显。抗性亲本为负值,感病亲本为正值;(4)特殊配合力效应有正有负,方向性不明显;(5)抗性亲本一般配合力方差较大,特殊配合力方差较小,证明抗性亲本品种有较稳定的遗传效应。以上结果对抗病育种正确选配亲本将有一定意义。     

小麦新品系抗白粉病基因分析

 本文对6个小麦新品系所含的抗白粉病基因进行了遗传分析。将感病品种Liaochun10分别与SM 20121、SM 203390、SM 20125、SM 200332、SM 20126、SM 20005杂交和自交,并将这6个品系互配成半双列杂交组合。用小麦白粉菌15号小种的单孢堆菌系对各杂交组合的亲本、F₁、F₂代群体及F₃代家系进行了苗期抗病性鉴定。遗传分析表明,供试的6个品系对小麦白粉菌15号小种的抗性均由1对显性基因控制。等位性分析推断:SM 20121、SM 203390、SM 20125和SM 200332含有抗白粉病基因Pm12;SM 20126含有抗白粉病基因Pm21;SM 20005含有抗白粉病基因Pm16。建议将这6个品系作为优良抗病亲本利用。     

珍龙13和窄叶青8号抗稻瘟病遗传分析

 用稻瘟病(Pyricularia oryzae)的菌株75-49和0206-1(分别代表ZB和ZC群小种)接种抗病品种窄叶青8号、珍龙13与感病品种朝六早、朝阳一号的杂交组合,根据F₁、F₂、F₃和B₁F₁分析结果,窄叶青8号对菌株75-49和0206-1的抗性由两对抗性基因控制,而珍龙13对菌株0206-1的抗性由单显性抗性基因控制。     

农家品种‘白大头’及其衍生系‘天00127’苗期抗条锈性遗传分析

2019年在甘肃省农业科学院植物保护研究所兰州温室,对抗条锈性优异的农家品种‘白大头’及其衍生系‘天00127’与感病品种‘铭贤169’杂交组合的P₁、P₂、F₁、F₂和BC₁代材料,苗期分别人工接种条锈菌主要流行小种CYR34、CYR32的单孢菌系,进行抗病性遗传分析,结果表明：供试亲本‘白大头’和‘天00127’对CYR34和CYR32均表现免疫。各世代材料中,‘铭贤169’/‘白大头’组合与‘铭贤169’/‘天00127’组合的F₁代对供试小种均表现免疫或近免疫;F₂代植株表现抗感分离,其中‘铭贤169’/‘白大头’组合对CYR34符合1R∶3S的理论比值,对CYR32符合3R∶1S的理论比值;BC₁代植株对CYR34表现全感,对CYR32符合1R∶1S的理论比值;‘铭贤169’/‘天00127’组合对CYR34和CYR32均符合3R∶1S的理论比值;BC₁代植株抗感分离符合1R∶1S...     

玉米抗青枯病基因的遗传分析

 本研究对2亲本1145和Y331、杂交F₁以及F₂群体进行玉米青枯病单一致病菌(肿囊腐霉菌)的接种鉴定,统计F₂群体中抗病、感病植株分离情况,并作了初步统计分析。结果表明:单一肿囊腐霉菌也能引起玉米青枯病;玉米对肿囊腐霉菌引起青枯病的抗性由显性单基因控制。     

西瓜抗小西葫芦黄花叶病毒基因的连锁分子标记研究

 小西葫芦黄花叶病毒中国株系(Zucchini yellow mosaic virus Chinese strain,ZYMV-CH)是危害我国西瓜的主要病毒。本实验以抗病毒病西瓜野生种质P.I.595203与感病的普通西瓜自交系98R为亲本,采用单粒传方式得到109个E代株系,分别对亲本、F₁及109个F₃代株系群体进行了苗期抗ZYMV-CH接种鉴定,通过F₃代群体的抗感分离情况,推测得到F₂代各单株的基因型,采用集团分离分析法(bulked segregant analysis,BSA)在F₂代建立抗感基因池,以亲本、F₁和抗感基因池为模板,对640条RAPD引物进行PCR扩增筛选,其中引物AK13在亲本、F₁和抗感基因池之间扩增出一条多态性片段(644bp),在F₂代群体上验证该多态性条带与ZYMV-CH的抗性基因呈现连锁关系,遗传连锁距离为8cM,定名为AK13_-644,该连锁标记在ZYMV-CH抗性转育后代自交系上得到了验证。最终将此RAPD标记成功转化成SCAR标记SCAK13_-644,该标记可以作为西瓜抗病毒病辅助选择的分子标记。     

水稻白叶枯病抗性基因在不同载体品种上及杂种F_1的抗性研究

本研究测试了八个水稻白叶枯病抗性基因Xa3、Xa4、xa5、Xa7、Xa10、Xa11、Xa14和Xa23在相应载体品种上对华南白叶枯病优势致病菌系Ⅳ型菌和强毒菌系Ⅴ型菌的抗性反应;分析了Xa4、xa5、Xa7和Xa23抗病基因与不同感病品种杂交组合F_1的抗性表达模式以及显性抗病基因Xa7和Xa23在杂交水稻上的利用价值。结果表明:大部分抗性基因在不同载体品种上抗性表达一致,但也有少数基因在不同载体品种上抗性表现不一,甚至截然相反,说明不同遗传背景对抗性表达有影响,而这种影响因不同抗性基因而异。隐性抗病基因xa5(IRBB5)和显性抗病基因Xa23(CBB23)与感病亲本组合的F_1代分别表现感病和抗病,符合隐性基因或显性基因的抗性表达模式;而2个显性抗病基因Xa4(IRBB4))和Xa7(IRBB7)与感病亲本组合的F_1代,有部分组合的F_1代表现抗病,符合显性基因的抗性表达模式,有部分组合的F_1代表现感病,不符合显性基因的抗性表达模式。在杂交水稻上的利用价值方面,Xa7与2个不育系组合的F_1代均表现高感,不宜在杂交水稻上利用;Xa23(CBB23)与4个感病亲本,无论是不育系还是常规稻组合的4个F_1代全部表现抗病,抗性在F_1充分表达,在杂交水稻上有重要的利用价值。     

水稻抗病性的遗传研究Ⅰ.水稻对白叶枯病抗性的遗传

 在1983-84两年中,用赣W-2和赣S-3两白叶枯病菌株分别接种8个杂交水稻组合的亲本、F₁、F₂和F₃代的结果表明,各抗病亲本所具有的抗W-2菌株的基因数目和作用方式均与其抗S-3菌株的基因数目和作用方式相同。就对W-2或S-3菌株的单一抗性来说,早36具有2对显性抗病基因;VT34-1具有2对互补的显性抗病基因;IR26和3624-33都具有3对互补的显性抗病基因。
在VT34-1中,有1对基因既控制对W-2菌株的抗性又控制对S-3菌株的抗性,另外2对基因则分别控制对这两菌株之一的抗性。在早36中,抗W-2菌株的2个独立基因分别与抗S-3菌株的2个独立基因连锁,其配子重组值为13.3%,基因重组值为6.887%。在IR26和3624-33中,抗W-2的菌株的3个独立基因均与抗S-3菌株的3个独立基因连锁,但它们的配子重组值和基因重组值均无法估计。预料同时选择对W-2和S-3菌株的抗性非常容易。     

玉米粗缩病抗性遗传研究

 本文选用3个抗病自交系(齐319、X178、沈137)和3个感病自交系(掖107、掖478、沈5003)按照NCII交配设计配制9套杂交组合研究了玉米抗粗缩病遗传规律。2009-2010年在曲阳、保定采用田间自然发病方法鉴定亲本、F₁、F₂群体的玉米粗缩病抗性,并采用灰飞虱人工接种方法鉴定亲本材料的抗病性。运用QGA station 软件的加性-显性-上位性(ADAA)遗传模型进行数据分析,结果表明,显性效应和加性效应是控制玉米粗缩病抗性的主要遗传组分,分别占表型变异的44.8%和13.1%,杂合显性效应表现负向杂种优势,抗病育种可加以利用。加性×加性上位性效应在玉米自交系和杂交组合抗粗缩病遗传中普遍存在,但因材料不同而表现负向或正向效应。玉米粗缩病抗性易受环境影响,显性与环境互作效应方差占表型方差的比率为39.8%,达到极显著水平。因此,培育抗粗缩病玉米品种应依据基因型选配适当的亲本材料,抗病品种宜进行多年多点鉴定筛选。     

小麦秆锈菌鉴别寄主品种Orofen对小种21C3和34C2抗病基因的单体分析

 用中国春单体系列和二体中国春作为母本与Orofen杂交。选择出所有类型的单体杂种F1植株,令其自交结实。在温室内(10-25℃)用秆锈菌小种21C3和34C2的单孢菌系分别接种鉴定各杂交组合的F₂代苗期的抗性分离表现。对小种21C3,除2D和6D之外,其它单体类型和二体对照的F₂代都符合抗病15:1感病的分离比例;对小种34C2,除2D之外,其它单体类型和二体对照的F₂代都符合抗病3:1感病的分离比例。用Orofen与含有国际上已定位于2D和6D染色体上的已知Sr基因的品系(或品种)杂交。对小种21C3,Orofen与含有Sr5和Sr6的单基因系的杂交F₂未分离出感病的植株;对小种34C2,只有与含有Sr6的单基因系的杂交F₂代未分离出感病的植株。这表明,Orofen在2D染色体上含有Sr6,它兼抗小种21C3和34C2,分别提供0-1;1⁺⁺x^-和;1-;1⁺⁺x^-的抗性效应;而在6D染色体上携带抗病基因Sr5,它只抗小种21C3.控制0-;1^-的侵染型。对无毒性的小种,Sr5对Sr6的抗病效应是上位的。     

Effect of exposure period on degree of dominance of phosphine resistance in adults of Rhyzopertha dominica (Coleoptera: Bostrychidae) and Sitophilus oryzae (Coleoptera: Curculionidae)

Degree of dominance of phosphine resistance was investigated in adults of Rhyzopertha dominica F and Sitophilus oryzae L. Efficacy of the grain fumigant phosphine depends on both concentration and exposure period, which raises the possibility that dominance levels vary with exposure period. New and published data were used to test this possibility in adults of R dominica and S oryzae fumigated for periods of up to 144 h. The concentrations required for control of homozygous resistant and susceptible strains and their F1 hybrids decreased with increasing exposure period. For both species the response lines for the homozygous resistant and susceptible strains and their F1 hybrids were parallel. Therefore, neither dominance level nor resistance factor was affected by exposure period. Resistance was incompletely recessive and the level of dominance, calculated at 50% mortality level, was -0.59 for R dominica and -0.65 for S oryzae. The resistant R dominica strain was 30.9 times more resistant than the susceptible strain, compared with 8.9 times for the resistant S oryzae strain. The results suggest that developing discriminating doses for detecting heterozygote adults of either species will be difficult.     

Inheritance of Resistance to Leptosphaeria maculans in Brassica juncea

ABSTRACT The inheritance of resistance to Leptosphaeria maculans, the causal agent of black leg of crucifers, was studied in Brassica juncea. Three resistant accessions (UM3021, UM3043, and UM3323) and one susceptible accession (UM3132) of B. juncea were crossed in a complete diallel. Parents, F(1), and F(2) progenies were evaluated for all crosses using both cotyledon and stem inoculation. Cotyledon reaction was evaluated with two isolates of L. maculans, but stem reaction was evaluated with one isolate. Disease reactions observed for individual plants were the same for both inoculation methods and for both isolates of the pathogen for cotyledon reaction. No segregation was observed for the crosses between resistant accessions (UM3043 x UM3323 and UM3021 x UM3323), but a few susceptible plants were observed in the F(2) progeny of crosses between resistant parents (UM3021 x UM3043). This was probably due to heterozygosity in some parental plants of UM3021. For crosses be tween the susceptible parent and resistant parents, F(1) plants for two crosses were all resistant. For cross UM3132 x UM3021, some susceptible plants occurred, which was also suggestive of heterozygosity in UM3021. Although resistance in F(1) was dominant, for F(2) populations, segregation fit either 13:3, 3:1, or 1:3 ratios, indicating that resistance can be either adominant or recessive trait. F(3) families derived from some susceptible F(2) plants from crosses UM3021 x UM3132 and UM3043 x UM3132 were evaluated using the cotyledon inoculation method only. Segregation of F(2) plants and F(3) families in crosses involving resistant and susceptible parents indicated that the resistance to L. maculans in B. juncea is controlled by two nuclear genes with dominant recessive epistatic gene action.     

小麦苗期慢叶锈抗性配合力和基因效应的初步研究

 本文用6个亲本组配成双列杂交设计,分析了普通小麦苗期慢叶锈性的配合力及基因效应。结果表明,F₁代不同组合间苗期叶锈潜育期存在明显差别,多数组合表现正向杂种优势。该性状属于数量性状遗传,由加性效应和非加性效应共同控制。一般配合力和特殊配合力方差均达到极显著水准。不同亲本之间一般配合力效应差异显著。"80-57"的一般配合力效应为第一位,含有的有利显性基因也最多。选择配合力好的亲本进行组配是选育抗叶锈品种的积极有效的途径。     

Inheritance of Resistance to Aflatoxin Production in the Cross Between Corn Inbreds B73 and LB31

ABSTRACT The inheritance of resistance to aflatoxin production in corn (Zea mays) caused by the fungus Aspergillus flavus was studied following inoculation in progeny derived from the cross between the susceptible inbred B73 and the resistant inbred LB31. In 1993, the susceptible parent B73 (P(1)), resistant parent LB31 (P(2)), F(1), F(3), and BCP(1)-selfed generations were evaluated. In 1994, the study was expanded to include the F(2), BCP(1), and BCP(2) generations. Aflatoxin concentrations were higher in 1993 than 1994. Generation mean analysis showed that additive and dominant gene action were important for resistance to aflatoxin production. Potence ratios indicated dominance for resistance in both years. In 1993, aflatoxin values of the F(1) generation were significantly lower than the calculated mid-parent values, indicating dominant gene action favoring resistance. In 1994, values of the F(1) generation were not significantly lower than the calculated midparent value. The frequency distributions of aflatoxin values for families of the F(3) and BCP(1)-selfed generations were skewed toward the resistant parent, also indicating dominance. Heritability based on a progeny mean basis of F(3) families representing the additive variance plus one-fourth of the dominance variance was estimated at 66% over both years combined. Based on these results, selection for resistance to aflatoxin production in progeny derived from the cross between B73 and LB31 should be effective.     

抗真菌转基因水稻纹枯病抗性的杂种优势分析

用抗纹枯病的12个转入l～4个外源抗真菌基因的转基因水稻作父本,分别与2～3个雄性不育系配组,采用田间人工接种纹枯病菌的方法,从3个抗性指标上研究了转基因杂交水稻纹枯病抗性的杂种优势.结果表明,杂交水稻的抗病性与转基因父本显著正相关,抗病性的广义遗传力为0.52～0.83.在29个杂交组合中,有5个组合具有显著负向超低亲(父本)优势,但群体平均超低亲优势大于0,为35.01%～50.79%;杂交稻群体的平均负向竞争优势明显,强度大,为-57.60%～-31.23%,有38%的组合具有显著负向竞争优势,说明转基因杂交水稻的抗纹枯病性普遍低于转基因水稻父本,但仍具有较好抗性,并可从中筛选出强优势组合.     

Relationship Among Genes Conferring Partial Resistance to Leaf Rust (Puccinia triticina) in Wheat Lines CI 13227 and L-574-1

ABSTRACT This study describes the segregation of genes for resistance to the fungus Puccinia triticina in a cross between partially resistant wheat lines L-574-1 and CI 13227 with two and four genes for resistance, respectively. The objectives of this study were to use parental, F(1), F(2), and backcross populations to quantify maternal effects, degree of dominance, and transgressive segregation, and to determine whether CI 13227 and L-574-1 share any resistance genes for long latent period or small uredinia. In two experiments conducted in the greenhouse, the uppermost leaf of adult wheat plants was inoculated prior to heading with P. triticina. On days 6 to 21 after inoculation, the number of uredinia that erupted from the leaf surface was counted and used to calculate the mean latent period (MLP). The length and width of five arbitrarily selected uredinia were measured and used to calculate uredinium area. Midparent values, degree of dominance, and broad-sense heritability were calculated for MLP and uredinium area. For experiment A, MLP values for CI 13227, L-574-1, F(1), and F(2) generations were 12.2, 10.5, 10.2, and 10.6 days, respectively. For experiment B, MLP values for CI 13227, L-574-1, F(1), F(2), backcross to CI 13227, and backcross to L-574-1 were 12.3, 10.0, 10.6, 10.8, 11.1, and 10.0 days, respectively. The inheritance of long latent period was partially recessive, and no maternal effect was present (P = 0.62 to 0.87 for the comparison of means in reciprocal crosses). Broad-sense heritability for MLP ranged from 0.72 to 0.74, and there was transgressive segregation in the F(2) and backcross populations. Uredinia of the F(1) generation were slightly larger than uredinia for CI 13227. The inheritance of uredinium size was partially dominant, and no maternal effect was present (P = 0.5 to 0.63). Broad-sense heritability for uredinium area ranged from 0.36 to 0.73 and transgressive segregation was present in the F(2) and backcross populations. The results for MLP indicate that lines CI 13227 and L-574 likely share one gene for resistance (based on F(1) values) but not two genes (based on the presence of transgressive segregation). CI 13227 and L 574-1 appear to have at least one gene difference for uredinium area. The linear relationship between uredinium area regressed onto MLP was significant (P < 0.001) and r(2) values ranged from 0.14 to 0.26. These results indicate that the resistance in CI 13227 and L-574-1 could be combined to create wheat cultivars with greater partial resistance than that possessed by either parent based on MLP or uredinium size.     

Agronomic performance of F1, F2 and F3 hybrids between weedy rice and transgenic glufosinate-resistant rice

BACKGROUND: Studies of hybrid fitness, of which agronomic performance may be an indicator, can help in evaluating the potential for introgression of a transgene from a transgenic crop to wild relatives. The objective of this study was to assess the agronomic performance of reciprocal hybrids between two transgenic glufosinate‐resistant rice lines, Y0003 and 99‐t, and two weedy rice accessions, WR1 and WR2, in the greenhouse. RESULTS: F₁ hybrids displayed heterosis in height, flag leaf area and number of spikelets per panicle. The agronomic performance of F1 between WR1 and Y0003 was not affected by crossing direction. The tiller and panicle numbers of F1 individuals were higher than their F2 counterparts. However, these traits did not change significantly from the F2 to the F3 generation or in hybrids with weedy rice as maternal or paternal plants. For all hybrids, the in vitro germination rates of fresh pollen were similar and significantly lower than those of their parents, seed sets were similar to or of lower value than those of weedy rice parents and seed shattering characteristics were partially suppressed, but the survival of hybrids over winter in the field was similar to that of weedy rice parents. All F1, F2 and F3 hybrids had similar composite agronomic performance to weedy rice parents. CONCLUSION: There was no significant decrease in the composite agronomic performance of any of the hybrids compared with weedy rice. This implies that gene flow from transgenic cultivated rice to weedy rice could occur under natural conditions. Copyright © 2011 Society of Chemical Industry     

小麦-滨麦易位系M8657-1抗条锈病基因遗传分析和分子标记

 M8657-1, one of the wheat translocation lines derived from Leymus mollis Trin. Hara, is possessed of effective resistance at all stages to Su-ll and other dominant races of Puccinia striiformis f. sp. tritici in China. Seedlings of the parents, F₁, and F₂ progeny derived from the cross of M8657-1 (resistant) Mingxian169 (susceptible) were inoculated with Su-ll in greenhouse to identify and map the probable new stripe rust resistance gene. The results suggested that the stripe rust resistance in M8657-1 was conferred by a pair of recessive genes. Simple sequence repeat (SSR) technique was used to detect molecular marker associated with the resistance gene:208 pairs of wheat SSR primers were used to screen the two parents, as well as resistant and susceptible bulks and then three SSR markers were selected for genotyping the F₂ population. The geue, temporarily designated as YrLml, was found to be located on the chromosome 7DL and flanked by three SSR markers GDM67, WMC150 and WMC671, with the genetic distance of 5.0, 9.7 and 11.8cM, respectively.     

Sources and genetics of crown rust resistance in barley

ABSTRACT Crown rust, caused by Puccinia coronata var. hordei, is a new disease threat to barley in the Great Plains region of the United States. Deployment of resistant cultivars is the only economically viable option for the control of this disease. Thus, the objective of this study was to investigate the sources and genetics of crown rust resistance in barley. A geographically diverse sample of barley germ plasm collected around the world (526 accessions total) was evaluated at the seedling stage to P. coronata var. hordei, and only 10 accessions (1.9% of the total) were found resistant. These 10 accessions were also resistant at the adult plant stage in a greenhouse test. Three F(2) populations (Bowman x Hor2596, MR x Hor2596, and MD x Hor2596) were developed to study the inheritance of crown rust resistance in the resistant line Hor2596 (CIho 1243). A close fit to a 3:1 ratio of resistant/susceptible plants was observed in all three populations and is consistent with the segregation of a single resistance gene. F(1) plants from the Bowman x Hor2596 population exhibited slightly higher infection types than the resistant parent, indicating incomplete dominance. The locus symbol Rpc1 and allele symbol Rpc1.a were recommended for the crown rust resistance gene in Hor2596. An attempt was made to associate the Rpc1 locus with one of the seven barley chromosomes by analyzing linkage data with previously mapped morphological markers in crosses with multiple recessive (MR) and multiple dominant (MD) morphological marker stocks. However, no close linkages were detected between Rpc1 and the 20 morphological markers present in the marker stocks. The resistant accessions identified in this study should be useful to breeders for developing barley germ plasm with crown rust resistance.     

Studies on the inheritance of resistance to metalaxyl in Phytophthora infestans

Single-oospore progeny from matings between field isolates of Phytophthora infestans either highly resistant or sensitive to metalaxyl were analysed for fungicide sensitivity in vitro, mating type and, in some cases, allozyme variation at the locus for glucosephosphate isomerase ( GPI-1. ) In each cross the majority of first-generation (F₁) progeny showed intermediate sensitivity to metalaxyl. Frequency distributions were skewed towards sensitivity and a few progeny were either wholly sensitive or resistant phenotypes. Allozyme analysis of F₁ progeny from a cross between parents of Dutch and Mexican origin showed that c. 10% were selfs of both parents and of parental phenotype for metalaxyl sensitivity. The selfs of the A2 but not the Al parent segregated for mating type. Two backcross generations to the metalaxyl-resistant Dutch parent gave unexpected phenotypic frequency distributions and aberrant ratios for genotypes at the GPI-I locus.
Progeny of another backcross between an F₁ isolate of intermediate sensitivity and its sensitive Egyptian parent gave a 1:1 ratio for sensitive: intermediate phenotypes. F₂ progeny from a related sibmating between intermediate phenotypes segregated in a ratio close to 1:2:1 for sensitive: intermediate: resistant phenotypes. Segregation was also observed among sexual progeny of an intermediate self-fertile isolate from the backcross generation but not among progeny of a resistant self-fertile phenotype. Mating type segregated in both cases.
These data are consistent with resistance to metalaxyl in P. infestans being governed by a single nuclear locus exhibiting incomplete dominance. This hypothesis is discussed in relation to the incidence of resistance to metalaxyl in natural populations of P. infestans.