Evaluation of Elite Rice Varieties Unmasks New Sources of Bacterial Blight and Leaf Streak Resistance for Africa

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Issa Wonni
Keyword(s):  
Bacterial Blight ◽  
Rice Varieties

scholarly journals Dynamics of bacterial blight disease in resistant and susceptible rice varieties

2022 ◽  
Author(s):  
Jennifer T. Niones ◽  
Ryan T. Sharp ◽  
Dindo King M. Donayre ◽  
Eula Gems M. Oreiro ◽  
Alice E. Milne ◽  
...  
Keyword(s):  
Primary Infection ◽  
Bacterial Blight ◽  
Short Range ◽  
Disease Incidence ◽  
The Philippines ◽  
Resistant Variety ◽  
Rice Varieties ◽  
Infection Efficiency ◽  
Spatial Spread ◽  
Secondary Spread

AbstractBacterial blight (X. oryzae pv. oryzae) is a serious disease in rice across the world. To better control the disease, it is important to understand its epidemiology and how key aspects of this (e.g. infection efficiency, and spatial spread) change according to environment (e.g. local site conditions and season), management, and in particular, variety resistance. To explore this, we analysed data on the disease progress on resistant and susceptible varieties of rice grown at four sites in the Philippines across five seasons using a combination of mechanistic modelling and statistical analysis. Disease incidence was generally lower in the resistant variety. However, we found no evidence that the primary infection efficiency was lower in resistant varieties, suggesting that differences were largely due to reduced secondary spread. Despite secondary spread being attributed to splash dispersal which is exacerbated by wind and rain, the wetter sites of Pila and Victoria in south Luzon tended to have lower infection rates than the drier sites in central Luzon. Likewise, we found spread in the dry season can be substantial and should therefore not be ignored. In fact, we found site to be a greater determinant of the number of infection attempts suggesting that other environmental and management factors had greater effect on the disease than climate. Primary infection was characterised by spatially-random observations of disease incidence. As the season progressed, we observed an emerging short-range (1.6 m–4 m) spatial structure suggesting secondary spread was predominantly short-range, particularly where the resistant variety was grown.

scholarly journals Genome Resource of a Hypervirulent Strain LN4 of Xanthomonas oryzae pv. oryzae Causing Bacterial Blight of Rice

Plant Disease ◽  
2020 ◽  
Vol 104 (11) ◽  
pp. 2764-2767
Author(s):  
Zhengyin Xu ◽  
Sai Wang ◽  
Liang Liu ◽  
Yangyang Yang ◽  
Bo Zhu ◽  
...  
Keyword(s):  
Bacterial Blight ◽  
Xanthomonas Oryzae ◽  
Nanopore Sequencing ◽  
Transcription Activator ◽  
Rice Varieties ◽  
Single Chromosome ◽  
Coding Sequences ◽  
Genome Data ◽  
Bacterial Blight Of Rice ◽  
Virulence Effectors

Xanthomonas oryzae pv. oryzae is the causative agent of bacterial blight of rice and causes severe harvest loss and challenges to a stable food supply globally. In this study, a hypervirulent strain, LN4, compatible in rice varieties carrying Xa3, Xa4, xa13, and xa25 resistance genes, was used to generate DNA for nanopore sequencing. After assembly, the genome comprises a single chromosome of 5,012,583 bp, consisting of a total of 6,700 predicted coding sequences. Seventeen transcription activator-like effectors (TALEs) were encoded in the genome, of which two (Tal7 and Tal6c) were major TALEs. The approach and genome data provide information for the discovery of new virulence effectors and understanding of the virulence mechanism of TALEs in rice.

scholarly journals Marker-assisted selection for transfer of submergence tolerance, bacterial blight resistance and yield enhancement in the rice backcross derivatives

2020 ◽  
pp. 1288-1294
Author(s):  
Shibani Mohapatra ◽  
Akshaya Kumar Bastia ◽  
Alok Kumar Panda ◽  
Sharat Kumar Pradhan
Keyword(s):  
Resistance Genes ◽  
Bacterial Blight ◽  
Rice Variety ◽  
Yield Component ◽  
Yield Enhancement ◽  
Yield Potential ◽  
Blight Resistance ◽  
Submergence Tolerance ◽  
Bacterial Blight Resistance ◽  
Rice Varieties

Achieving the demand and supply of rice for the increasing global population will be a challenging task beyond 2040. Therefore, the yield potential of popular rice varieties needs to be increased. The production from lowland rice can be enhanced by managing the major biotic and abiotic stresses faced in the ecology. In this work, we have developed the pipelines for gene stacking of submergence tolerance, bacterial blight resistance and yield component QTLs in the popular rice variety ‘Swarna’ by marker-assisted backcross breeding approach. Genotyping results of 796 BC1F1 backcross derived lines showed the presence of GW2, OsSPL14, SCM2 yield component QTLs, Sub1A for submergence tolerance and bacterial blight resistance genes xa5 and Xa21 in the progenies. The four stacked QTLs and two resistance genes were observed in six backcrosses derived progenies only. These progenies will be used in the next generation for further selection and evaluation for enhancing submergence tolerance, yield potential and bacterial blight resistance in Swarna rice variety background.

scholarly journals Applications of molecular markers for bacterial blight resistant varieties in rice (Oryza sativa L.)

2017 ◽  
Vol 9 (4) ◽  
pp. 2309-2314
Author(s):  
A. Premkumar ◽  
Manoj Kumar
Keyword(s):  
Molecular Markers ◽  
Molecular Marker ◽  
Bacterial Blight ◽  
Oryza Sativa L ◽  
Single Gene ◽  
Durable Resistance ◽  
Genetic Resistance ◽  
Recurrent Parent ◽  
Rice Varieties ◽  
Novel Technologies

Bacterial blight is one of devasting disease in almost all rice growing countries. The most effective, eco-nomic and environmental strategy for control of this disease is to develop rice varieties with genetic resistance. However, new pathotype has overcome single gene for resistance in the new cultivars. So, plant breeders are con-centrating to develop high yielding varieties with durable resistance using novel technologies. Molecular marker technology has progressed tremendously in the past decade for genetic improvement of field crops. Molecular markers can improve efficiency of breeding in different ways for trait in segregating population like identify plants with target gene in maximum recovery portion of recurrent parent. The transfer of two or three genes into single variety with the help of molecular marker is expected to lead to more durable resistance. Thus, thus review describes progress made in the development of bacterial blight resistance rice varieties using Marker Assisted Selection.

scholarly journals Assessment of potentiality of known bacterial blight resistant genes against Xanthomonas oryzae pv. oryzae pathotypes exist in Bangladesh

2021 ◽  
Vol 6 (3) ◽  
pp. 257-267
Author(s):  
Md. Mahbubul Haque ◽  
Md. Mostafa Masud ◽  
Md. Mokarram Hossain ◽  
Md. Mamunur Rashid ◽  
Md. Zahangir Alam ◽  
...  
Keyword(s):  
Host Resistance ◽  
Bacterial Blight ◽  
Xanthomonas Oryzae ◽  
R Gene ◽  
R Genes ◽  
Near Isogenic Lines ◽  
Rice Varieties ◽  
Isogenic Lines ◽  
Resistant Genes ◽  
Resistance Reaction

Bacterial blight (BB) caused by X. oryzae pv. oryzae is a destructive disease of rice and causes 30-50% losses to rice depending on the outbreak. Development BB resistant rice varieties have long been considered as one of the most effective approach to control the disease. However, the durability of host resistance is breaking down due to the change of pathotypes of X. oryzae pv. oryzae globally. Pathotypic analyses of 239 X. oryzae pv. oryzae Bangladeshi isolates on Near Isogenic Lines (NILs) containing resistance (R) gene (s) revealed the existence of eight pathotypes of X. oryzae pv. oryzae. Among eight pathotypes, pathotypes IV and V were considered as major comprising  maximum number of isolates, (30.13% and 23.01%, respectively), whereas pathotype VIII considered as minor consisting only 2.51% of total isolates. Pathotype, I showed highest virulence or aggressiveness compatible with all NILs, whereas pathotype VIII exhibited lowest virulence to these NILs. Bacterial blight resistant genes viz. Xa1 (75.00%), Xa11 (62.50%) and Xa21 (50.00%) showed resistance to most of the pathotypes while Xa4 performed worst as compared to all others R-genes. In pyramid lines, IRBBB63 (Xa5+Xa7+Xa13) and IRBB57 (Xa5+Xa7 +Xa21) showed resistance reaction and IRBB61 (Xa4+Xa5+Xa7), IRBB60 (Xa4+Xa5+Xa13+Xa21), IRBB54 (Xa5+Xa21), and IRBB53 (Xa4+Xa21) showed susceptible reaction to X. oryzae pv. oryzae pathotypes. These results collectively indicated the deployment of Xa1, Xa11, Xa4, Xa5, Xa7, Xa13 and Xa21 either alone or in combination against BB would be a best choice for the development of BB resistant rice varieties in Bangladesh.

scholarly journals Marker-assisted pyramiding of two major broad-spectrum bacterial blight resistance genes,Xa21andXa33into an elite maintainer line of rice, DRR17B

2018 ◽  
Author(s):  
CH Balachiranjeevi ◽  
S Bhaskar Naik ◽  
V Abhilash Kumar ◽  
G Harika ◽  
H.K Mahadev Swamy ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Bacterial Blight ◽  
Durable Resistance ◽  
Gene Pyramiding ◽  
Resistance Breeding ◽  
Fertility Restorer ◽  
Rice Varieties ◽  
Homozygous Condition ◽  
Specific Pcr ◽  
High Level

AbstractBacterial blight (BB) disease reduces the yield of rice varieties and hybrids considerably in many tropical rice growing countries like India. The present study highlights the development of durable BB resistance into the background of an elite maintainer of rice, DRR17B, by incorporating two major dominant genes,Xa21andXa33through marker-assisted backcross breeding (MABB). Through two sets of backcrosses, the two BB resistance genes were transferred separately to DRR17B. In this process, at each stage of backcrossing, foreground selection was carried out for the target resistance genes and for non-fertility restorer alleles concerning the major fertility restorer genesRf3andRf4, using gene-specific PCR-based markers, while background selection was done using a set of 61 and 64 parental polymorphic SSR markers respectively. Backcross derived lines possessing eitherXa21orXa33along with maximum genome recovery of DRR17B were identified at BC3F1generation and selfed to develop BC3F2s. Plants harboringXa21orXa33in homozygous condition were identified among BC3F2s and were intercrossed with each other to combine both the genes. The intercross F1plants (ICF1) were selfed and the intercross F2(ICF2) plants possessing bothXa21andXa33in homozygous condition were identified with the help of markers. They were then advanced further by selfing until ICF4generation. Selected ICF4lines were evaluated for their resistance against BB with eight virulent isolates and for key agro-morphological traits. Six promising two-gene pyramiding lines of DRR17B with high level of BB resistance and agro-morphological attributes similar or superior to DRR17B with complete maintenance ability have been identified. These lines with elevated level of durable resistance may be handy tool for BB resistance breeding.

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