Saturating genomic regions spanning QNR6.1 and QNR12.2 associated with root-knot nematode resistance in rice

Simple item page
dc.contributor.advisorYogesh Vikal
dc.contributor.authorShabneek Kaur
dc.date.accessioned2024-03-04T10:05:23Z
dc.date.available2024-03-04T10:05:23Z
dc.date.issued2023
dc.description.abstractM. graminicola, a potent organism causing the root-knot nematode (RKN) disease, can be found in most of the areas in India. Due to lack of effective chemical control, most effective strategy to combat the RKN is finding new resistant sources and its deployment in elite rice cultivars. Tagging and fine mapping is a pre-requisite for transfer of RKN resistant genes through marker-assisted selection (MAS). Among the wild varieties, O. glaberrima has been proved to be a resistant donor for nematode resistance. A cross was generated between O. glaberrima acc. IRGC 102206 and O. sativa cv. PR121 to transfer the genes for resistance into the commercial cultivar. The potential QTLs, through BSA QTL-seq approach were identified and two of the QTLs qNR6.1 and qNR12.2 were considered major QTLs. Therefore, present investigation aimed to fine map these QTLs identified for nematode resistance. Phenotypic evaluation of BC2F2 and BC2F3 progenies for the morphological traits such as gall number, root length and plant height is done. The genetic studies for gall number revealed that nematode resistance is governed by single dominant gene in O. glaberrima. The BC2F2 and BC2F3 progenies segregated in the desired ratio of 3:1 and 1:2:1, respectively for single gene inheritance. A total of 37 SSR and 33 KASP markers targeting qNR6.1 region and 16 SSR markers targeting qNR12.2 region were surveyed for parental polymorphism. The 17 polymorphic markers were genotyped on BC2F2 population. The total map length obtained was 1.034 Mb which was saturated from the original region of 3 Mb. Two QTL peaks flanked by markers NRK_13 & NRK_20 and NRK_21 & RM7158 were detected within the qNR6.1 region explaining 29.87% of total phenotypic variance. The new detected region needs to be saturated with more markers so that MAS can be followed for root-knot nematode resistance rice breeding programs. A total of 42 potential candidate genes were detected within the QTL region and probably six of them have putative role in nematode resistance. Further, role of candidate genes could be explored to understand the rice root knot nematode resistance mechanism.
dc.identifier.citationShabneek Kaur (2023). Saturating genomic regions spanning QNR6.1 and QNR12.2 associated with root-knot nematode resistance in rice (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.
dc.identifier.urihttps://krishikosh.egranth.ac.in/handle/1/5810207332
dc.keywordsM. graminocola
dc.keywordsBSA QTL-seq
dc.keywordsrice
dc.keywordsRKN
dc.keywordsO. glaberrima.
dc.language.isoEnglish
dc.pages67
dc.publisherPunjab Agricultural University
dc.research.problemSaturating genomic regions spanning QNR6.1 and QNR12.2 associated with root-knot nematode resistance in rice
dc.subAgricultural Biotechnology
dc.themeSaturating genomic regions spanning QNR6.1 and QNR12.2 associated with root-knot nematode resistance in rice
dc.these.typeM.Sc
dc.titleSaturating genomic regions spanning QNR6.1 and QNR12.2 associated with root-knot nematode resistance in rice
dc.typeThesis
Files
Collections
Thesis