Improvement of bacterial blight resistance of the popular variety, Nellore Mahsuri (NLR34449) through marker-assisted breeding

Aleena Dasari,Padma Vemulapalli,Kousik Muppavarapu,Laxmi Prasanna Butam,Dilip Kumar Thota,Venkata Subba Rao Lella,Laha Gouri Shankar,Punniakotti Elumalai,Pragya Sinha,Anila Miriyala,Ayyappa Dass Muralidhara,Hajira Shaik,Anantha Madhavenkatapura Siddaih,Srinivas Prasad Madamsetty,Balachandran Sena,Mastanbee Shaik,Harika Gunukula,Vijay Gopal Avula,Rekha Gonuguntla ,Lal Ahamed Mohammad ,Venkata Ramana Jagarlamudi ,Ratna Babu Didla ,Ravindra Ramrao Kale ,C Gireesh ,K Pranathi ,Swapnil Ravindra Kulkarni ,R M Sundaram

doi:10.1007/s12041-021-01340-z

Abstract

To combat the dreaded diseases in rice like bacterial blight (BB) and blast, host plant resistance has been advocated as the most suitable and sustainable method. Through the present study, we have successfully incorporated three major BB resistance genes, namely Xa21, xa13 and xa5 into NLR3449, a high yielding, blast resistant, fine-grain type, popular rice variety through marker-assisted backcross breeding. Foreground selection was carried out using polymerase chain reaction based, gene-specific markers, namely pTA248 (Xa21), xa13prom (xa13) and xa5FM (xa5) at each generation of backcrossing, while 127 polymorphic SSR markers spanning on 12 chromosomes were used for background selection and backcrossing was limited to two rounds. At BC2F1 generation, a single plant (NLR-87-10) with 89.9% recovery, possessing all the three BB resistance genes was forwarded to BC2F2 generation. A solitary BC2F2 plant, namely NLR-87- 10-106 possessing all the three resistance genes and 96% genome recovery was identified and advanced through selfing until BC2F4 generation by adopting pedigree-method of selection. Three best BC2F4 lines, possessing high level of resistance against BB and blast, and equivalent or superior to NLR 34449 in terms of yield, grain quality and agro-morphological traits were identified and advanced for multilocation trials.

Highlights

Rice is an important food crop that serves as a major carbohydrate source for nearly half of the world’s population (Nguyen and Ferrero 2006; Sundaram et al 2008 and Pradhan et al 2015)
Rice is affected by many diseases and among them, bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) (Ishiyama, 1922) is known to cause yield losses ranging from 74%-81% (Srinivasan and Gnanamanickam 2005), when the disease occurs in severe form
They were subjected for foreground selection using genespecific markers and positive plants were analyzed for the recurrent parent genome recovery through background selection using a set of 127 SSR parental polymorphic markers evenly distributed across the 12 rice chromosomes to identify those plants with maximum recurrent parent genome recovery (RPG)

Summary

Introduction

Rice is an important food crop that serves as a major carbohydrate source for nearly half of the world’s population (Nguyen and Ferrero 2006; Sundaram et al 2008 and Pradhan et al 2015). It is grown throughout the year in a variety of agro-ecosystems in India, which include irrigated, rain-fed, deep-water and hills (Sundaram et al 2009). We need to produce at least 40% more rice by 2030 to feed a growing population and there are many challenges in meeting the food security requirements for the future (Khush 2005) This target has to be met amidst the scarcity of natural resources and adverse effects from a rapidly changing climate and with less use of chemicals and unde constant battle against new emerging pathogens and pests (Pradhan et al 2015). 45 BB resistant genes (Neelam et al 2019; Sundaram et al 2014; Suk-man Kim et al 2018) have been identified so far from the primary gene pool of rice and pyramiding two or more resistance genes has been advocated to enhance the durability of resistance (Sundaram et al 2008)

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Discussion

Conclusion