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Differences were found in the expression of resistance of perennial ryegrass, Lolium perenne, cultivars to crown rust, Puccinia coronata Corda, when plants were incubated at either 10°C or 25°C. In an extreme example, all the genotypes of ‘Carrick’ were resistant at 10°C but susceptible at 25°C. The variation between cultivars was due both to a general increase in expression of susceptibility and the proportion of plants which became susceptible. A BC1 line containing a stay‐green gene derived from Festuca pratensis was insensitive to temperature, while a sister line was sensitive. 相似文献
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Crown rust, Puccinia coronata Corda, causes one of the most damaging foliar diseases in Italian ryegrass, Lolium multiflorum Lam. For introgression of crown rust resistance, highly resistant hybrids of the crosses Festuca arundinacea (2n = 6x = 42) ×L. multiflorum (2n = 4x = 28) and reciprocally, L. multiflorum (2n = 2x = 14) ×Festuca pratensis (2n = 4x = 28) and subsequently resistant recombinant individuals were used as female parents and susceptible cultivars of Italian ryegrass as male parents in three successive backcrosses. The BC3 plants were selfed and crossed mutually. Uredospores of seven different crown rust isolates collected from plants of L. multiflorum, Lolium perenne, F. pratensis, F. arundinacea and L. multiflorum × F. pratensis hybrids were applied to identify the resistance or susceptibility of the parental species, backcrossed, selfed and intercrossed progenies. The various crown rust populations revealed a species-specific capability to infect plants of the Lolium-Festuca complex corresponding to the host species from which the spores originated. Selected BC9 plants, however, were found to be completely resistant to all crown rust populations tested. Successful introgression of the resistance was achieved from F. arundinacea as well as from F. pratensis. The resistance represents a dominant character, apparently based on a strong heterologous incompatibility between host and pathogen. In phenotype, bivalent formation during meiosis and in fertility, the novel germplasms are comparable with the L. multiflorum cultivars. 相似文献
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J. Šebesta 《Euphytica》1979,28(3):807-809
Summary In oat cv. Delphin (Bonda x Carstens Vii) two complementary genes were found conferring resistance to sixteen cultures of ten crown rust (Puccinia coronata
Cda. var. avenae
Fraser ET Led.) races. The complementary genes showed full dominance to eight races and incomplete dominance to two races. 相似文献
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Evidence of pathotypes among Australian isolates of crown rust infecting perennial ryegrass 总被引：2，自引：0，他引：2
Fifty‐three genotypes of perennial ryegrass selected from a range of cultivars and ecotypes were evaluated for their reaction to crown rust isolates collected from Western Australia, Victoria, Queensland, South Australia or New South Wales in Australia. The reactions of the clones to inoculation provided evidence for the development of a differential set of perennial ryegrass genotypes, but also demonstrated that a large number of genotypes displayed universal reactions to infection with any of the crown rust isolates. 相似文献
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Summary Parent-offspring regression was used to estimate heritability for three traits (-glucan content, groat percentage, and resistance to crown rust (Puccinia coronata Cda. f. sp. avenae Eriks.) in oat (Avena sativa L.). The populations used were derived from two crosses, Nova x Marion QC and Sylva x Marion QC. Marion QC was used as a parent because other research had shown that it is relatively high in -glucan, a trait for which heritability had not previously been estimated. Nova and Sylva are similar in adaptation to Marion QC, and Sylva may be a source of general resistance to crown rust. Random F5 plants were grown in a greenhouse, and their F6 and F7 progeny were grown in replicated field trials. Heritability estimates for the two grain quality traits were based on regression of F6 values on F5 values, F7 values on F6 values, and F7 values on F5 values. Heritability estimates for -glucan content were between 0.27 and 0.45. The highest estimate was the one based on the F6 and F7 generations of Sylva x Marion QC: 0.45, compared to estimates of 0.32 or less for earlier generations of the same cross, and to estimates of 0.35 or less for all generations of Nova x Marion QC. Heritability estimates for groat percentage were all between 0.23 and 0.32. The F6 and F7 generations were evaluated for resistance to crown rust resistance. The Sylva x Marion QC cross seemed to segregate for heritable resistance (h
2=0.31) but the Nova x Marion QC cross did not (h
2=0.07). Several lines from the Sylva x Marion QC cross had low symptoms in both the F6 and F7 generations. There were no strong genetic correlations among the traits. 相似文献
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三种麦类作物对叶(冠)锈菌非寄主抗病性与品种抗病性的组织病理学研究 总被引：2，自引：0，他引：2
比较研究了小麦、黑麦和燕麦对小麦叶锈菌、黑麦叶锈菌和燕麦冠锈菌的非寄主抗病性与品种抗病性的组织病理学特点。接种幼苗的荧光显微检查表明,非寄主抗病性除不同程度地中断侵入外,主要抑制侵染菌丝生长和吸器母细胞的形成,引起菌落早期败育和叶肉细胞坏死。这些特点与品种抗病性的过敏性坏死反应相同。这种类型的抗病性具有小种专化性,因而即使用遗传操作技术将这种非寄主抗病性转移到寄主品种中,也可能因病菌小种的变异而不会持久。 相似文献
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[目的]对江苏句容地区黑麦草锈病进行病原菌鉴定和发病规律研究。[方法]分别对2008年和2009年5月中旬至10月在江苏省句容市江苏农林职业技术学院科技示范园和校园的草坪绿化带发生的黑麦草锈病进行随机调查和发病规律观察。[结果]在江苏句容地区,黑麦草锈病每年6月份发生最严重,当年播种的幼嫩黑麦草比2年生成丛黑麦草更易感病;确定冠柄锈菌（Puccinia coronata var. coronata Corda）为句容地区的黑麦草锈病病原菌;25℃左右最适合锈病发生,当气温超过35℃时,病害减轻或停止。[结论]黑麦草锈病在江苏省为初次报道。 相似文献
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QTL analysis of crown rust resistance in perennial ryegrass under conditions of natural and artificial infection 总被引：2，自引：0，他引：2
Crown rust is an economically devastating disease of perennial ryegrass. Both artificial crown rust inoculations, with the possibility of several selection cycles in one year, as well as marker-assisted selection can be used for more efficient breeding of new resistant cultivars. The objective of this study was to map quantitative trait loci (QTL) for response to crown rust infection in perennial ryegrass. In order to identify relevant markers for response to crown rust infection, QTL mapping was performed on a ryegrass mapping population which was evaluated for resistance in the field for two years as well as by artificial pathogen inoculations using a detached leaf assessment. The broad sense heritability values for the field, detached leaf and combined assays were 0.42, 0.56, and 0.64, respectively, indicating a good potential for selection for crown rust resistance. A total of six QTLs were identified and mapped to linkage groups (LG) LG1, LG4 and LG5, explaining between 6.8% and 16.4% of the total phenotypic variation. 相似文献
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Breeding perennial ryegrass with better crown rust resistance 总被引：1，自引：0，他引：1
Improving rust resistance is one of the main goals in our breeding programme with perennial ryegrasses. We have studied the behaviour of our breeding material over several years in several locations under natural and artificial infection conditions. The narrow sense heritability of crown rust resistance is fairly high (0.46), providing scope for improving resistance, but this optimism is reduced by the negative correlation with yield. The most resistant material yielded 4% less than the most susceptible material. No decline in digestibility is expected when improving the disease resistance. The incidence of crown rust is very variable between years, locations and between spontaneous and artificial infections, creating constraints in selection. Observations for several years and at several locations appear to be the best way to improve rust resistance in perennial ryegrass. 相似文献