scholarly journals Utilização de análise de segregantes agrupados na identificação de marcadores ligados a genes que controlam a resistência à ferrugem (Puccinia psidii Winter) em Eucalyptus sp.

2008 ◽  
Vol 34 (3) ◽  
pp. 253-255 ◽  
Author(s):  
Karina Carnieli Zamprogno ◽  
Edson Luiz Furtado ◽  
Celso Luiz Marino ◽  
Cesar Augusto Bonine ◽  
Donizete Costa Dias

Devido a grande importância da cultura de Eucalyptus no Brasil, empresas do setor florestal têm buscado através de programas de melhoramento genético, reduzir as perdas de produção e atender a demanda do mercado de papel e celulose. Um exemplo, é a busca por genes de resistência a doenças, principalmente a ferrugem causada por Puccinia psidii Winter, que resulta em redução da produtividade em plantas altamente suscetíveis. No presente trabalho, mudas de Eucalyptus pertencentes a uma geração F1, provenientes do cruzamento controlado entre parentais híbridos E. grandis X E. urophylla, sendo eles resistente e suscetível, foram inoculadas com Puccinia psidii em casa de vegetação e acompanhadas até o aparecimento dos sintomas da ferrugem. Foram classificadas, em dois grupos: resistentes (ausência de sintomas) e suscetíveis (presença de sintomas e esporulação). As amostras de DNA foram comparadas com o uso de marcadores moleculares associado ao método de BSA (Bulked Segregant Analysis). O polimorfismo entre os grupos foi geneticamente relacionado ao loco que determina a característica de resistência ou sucetibilidade. Dentre os 720 "primers" testados, 19 foram polimórficos, porém, apenas o marcador AK 01 manteve-se presente, quando testado em todos os indivíduos da população, mostrando-se a uma distância genética estimada de 20 cM em repulsão ao gene de resistência.

Author(s):  
Junping Yu ◽  
Guolong Zhao ◽  
Wei Li ◽  
Ying Zhang ◽  
Peng Wang ◽  
...  

Abstract Key message Identification and functional analysis of the male sterile gene MS6 in Glycine max. Abstract Soybean (Glycine max (L.) Merr.) is an important crop providing vegetable oil and protein. The male sterility-based hybrid breeding is a promising method for improving soybean yield to meet the globally growing demand. In this research, we identified a soybean genic male sterile locus, MS6, by combining the bulked segregant analysis sequencing method and the map-based cloning technology. MS6, highly expressed in anther, encodes an R2R3 MYB transcription factor (GmTDF1-1) that is homologous to Tapetal Development and Function 1, a key factor for anther development in Arabidopsis and rice. In male sterile ms6 (Ames1), the mutant allele contains a missense mutation, leading to the 76th leucine substituted by histidine in the DNA binding domain of GmTDF1-1. The expression of soybean MS6 under the control of the AtTDF1 promoter could rescue the male sterility of attdf1 but ms6 could not. Additionally, ms6 overexpression in wild-type Arabidopsis did not affect anther development. These results evidence that GmTDF1-1 is a functional TDF1 homolog and L76H disrupts its function. Notably, GmTDF1-1 shows 92% sequence identity with another soybean protein termed as GmTDF1-2, whose active expression also restored the fertility of attdf1. However, GmTDF1-2 is constitutively expressed at a very low level in soybean, and therefore, not able to compensate for the MS6 deficiency. Analysis of the TDF1-involved anther development regulatory pathway showed that expressions of the genes downstream of TDF1 are significantly suppressed in ms6, unveiling that GmTDF1-1 is a core transcription factor regulating soybean anther development.


Genome ◽  
1997 ◽  
Vol 40 (2) ◽  
pp. 188-194 ◽  
Author(s):  
P. K. Subudhi ◽  
R. P. Borkakati ◽  
S. S. Virmani ◽  
N. Huang

The thermosensitive genetic male sterility (TGMS) system is considered to be a more efficient alternative to the cytoplasmic male sterility (CMS) system for hybrid rice. An F2 population from a cross between a TGMS mutant line (IR32364TGMS) and IR68 was used to map the TGMS gene tms3(t). Fertile and sterile bulks were constructed following the classification of F2 plants into true breeding sterile, fertile, and segregating fertile plants based on F3 family studies. From the survey of 389 arbitrary primers in bulked segregant analysis, four RAPD markers were identified in which three, OPF182600, OPB19750, and OPAA7550, were linked to tms3(t) in repulsion phase and one, OPAC3640, was linked to tms3(t) in coupling phase. The tms3(t) gene was flanked by OPF182600 and OPAC3640 on one side and by OPAA7550 and OPB19750 on the other side. All four markers were low-copy sequences and two of them (OPF182600 and OPAC3640) detected polymorphism when the markers were used to probe the genomic blots. Subsequently, OPAC3640 was mapped to the short arm of chromosome 6 using a mapping population available at IRRI. However, no RFLP markers from this region showed linkage to tms3(t) owing to the lack of polymorphism between the parents. All RAPD fragments were cloned and partially sequenced from both ends. Thus, PCR primers can be designed to develop PCR markers for marker-assisted breeding to facilitate the transfer of tms3(t) from one genetic background to another.Key words: bulked segregant analysis, gene tagging, marker-assisted selection, RAPD, TGMS.


2014 ◽  
Vol 14 (4) ◽  
pp. 244-250 ◽  
Author(s):  
Marisângela Rodrigues Santos ◽  
Lúcio Mauro da Silva Guimarães ◽  
Marcos Deon Vilela de Resende ◽  
Leonardo Novaes Rosse ◽  
Karina Carnielli Zamprogno ◽  
...  

Eucalypts rust (Puccinia psidii) is currently one of the major diseases in commercial eucalypt plantations in Brazil. The primary method of disease control is the use of resistant genotypes, and, among the different species of Eucalyptus, E. pellita is indicated as a promising source of resistance. In this work, the genetic control of rust resistance in E. pellita through inoculations under controlled conditions of 441 plants from four full-sibling families was studied. Inoculations were performed using the monopostular isolate UFV-2, race 1. All families tested segregated for rust resistance, and the number of resistant plants was higher than susceptible in all crosses. Inheritance models based on few genes did not fully explain the observed segregation patterns, and the narrow-sense heritability of rust resistance was estimated between 32.7% and 37.3%. The results suggested that rust resistance in E. pellita is complex and is controlled by major- and minor-effect genes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zaiqing Wang ◽  
Anmin Yu ◽  
Fei Li ◽  
Wei Xu ◽  
Bing Han ◽  
...  

AbstractPlant dwarfism is a desirable agronomic trait in non-timber trees, but little is known about the physiological and molecular mechanism underlying dwarfism in woody plants. Castor bean (Ricinus communis) is a typical woody oilseed crop. We performed cytological observations within xylem, phloem and cambia tissues, revealing that divergent cell growth in all tissues might play a role in the dwarf phenotype in cultivated castor bean. Based on bulked segregant analyses for a F2 population generated from the crossing of a tall and a dwarf accession, we identified two QTLs associated with plant height, covering 325 candidate genes. One of these, Rc5NG4-1 encoding a putative IAA transport protein localized in the tonoplast was functionally characterized. A non-synonymous SNP (altering the amino acid sequence from Y to C at position 218) differentiated the tall and dwarf plants and we confirmed, through heterologous yeast transformation, that the IAA uptake capacities of Rc5NG4-1Y and Rc5NG4-1C were significantly different. This study provides insights into the physiological and molecular mechanisms of dwarfing in woody non-timber economically important plants, with potential to aid in the genetic breeding of castor bean and other related crops.


Author(s):  
G. F. Laundon

Abstract A description is provided for Puccinia psidii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Pimenta officinalis and Psidium guajava, also on Callistemon speciosus, Eucalyptus citriodora, Eugenia jambos, E. malaccensis, E. uvalha, Marlierea edulis, Myrcia spp., Myrciaria jaboticaba and Pimenta acris. DISEASE: Guava rust. Attacks foliage, inflorescences and young succulent twigs of pimento and Eucalyptus, and foliage and fruit of guava, causing severe defoliation under certain conditions. GEOGRAPHICAL DISTRIBUTION: Central America and Caribbean (Cuba, Dominica, Dominican Republic, Jamaica, Puerto Rico, Trinidad); South America (Argentina, Brazil, Colombia, Ecuador, Paraguay, Uruguay, Venezuela). (CMI Map 181, Ed. 2, 1949 & Herb. IMI.) TRANSMISSION: Urediospores disseminated by rain-splash in Jamaica (41: 569).


2000 ◽  
Vol 90 (9) ◽  
pp. 1039-1042 ◽  
Author(s):  
G. M. Tabor ◽  
T. L. Kubisiak ◽  
N. B. Klopfenstein ◽  
R. B. Hall ◽  
H. S. McNabb McNabb

In the north central United States, leaf rust caused by Melampsora medusae is a major disease problem on Populus deltoides. In this study we identified molecular markers linked to a M. medusae resistance locus (Lrd1) that was segregating 1:1 within an intraspecific P. deltoides family (C9425DD). Previous field results were confirmed in the controlled environment of a growth chamber through an excised whole-leaf inoculation method. Using bulked segregant analysis we identified two random amplified polymorphic DNA (RAPD) markers (OPG10340 and OPZ191800) that are linked to Lrd1. Based on segregation in a total of 116 progeny, the genetic distances between OPG10340 and OPZ191800 and the resistance locus were estimated as 2.6 and 7.4 Haldane centimorgans (cM), respectively. Multipoint linkage analyses strongly suggest the most likely order for these loci is Lrd1, OPG10340, and OPZ191800. These markers may prove to be instrumental in the eventual cloning of Lrd1, as well as for marker-assisted selection of leaf-rust resistant genotypes.


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