Development of Broad Spectrum and Durable Bacterial Blight Resistant Variety through Pyramiding of Four Resistance Genes in Rice

Abstract

Bacterial blight (BB) disease caused by Xanthomonas oryzae pv. oryzae is a major biotic constraint on obtaining higher grain yields in rice. Marker-assisted backcross breeding (MABB) was performed by the pyramiding of Xa4, xa5, xa13 and Xa21 resistance genes in the popular variety, Ranidhan. A foreground selection in BC1F1, BC2F1, and BC3F1 progenies detected all the target genes in 12, 7 and 16 progenies by using the closely linked markers from a population size of 426, 410, and 530, respectively. The BB-positive progenies carrying the target genes with a maximal similarity to the recipient parent was backcrossed in each backcross generation. A total of 1784 BC3F2 seeds were obtained from the best BC3F1 progeny. The screening of the BC3F2 progenies for the four target genes resulted in eight plants carrying all the four target genes. A bioassay of the pyramided lines conferred very high levels of resistance to the predominant isolates of bacterial blight disease. In addition, these pyramided lines were similar to Ranidhan in 16 morpho-quality traits, namely, plant height, filled grains/panicle, panicles/plant, grain length, grain breadth, grain weight, milling, head rice recovery, kernel length after cooking, water uptake, the volume expansion ratio, gel consistency, alkali-spreading value, and the amylose content.

Incorporation of Two Bacterial Blight Resistance Genes into the Popular Rice Variety, Ranidhan through Marker-Assisted Breeding

“…Many elite donor lines with different resistance genes are being used in the BB resistance improvement programs [13]. The resistance genes, namely Xa4, xa5, Xa7, xa13 and Xa21, have been extensively utilized in BB resistance improvement programs [14][15][16]. Suitable combinations of BB resistance genes in a variety of backgrounds are reported to be effective against the pathogen isolates.…”

Generation of High-Value Genomic Resource in Rice: A “Subgenomic Library” of Low-Light Tolerant Rice Cultivar Swarnaprabha

“…Many advances have been made in the field of genomics [ 52 , 53 , 54 ] and transgenics [ 55 , 56 ] to impart biotic/abiotic tolerance [ 57 , 58 ] or engineer a trait in crops [ 59 ], but the genomic resources for low-light tolerance in plants are meagre. Therefore, a subgenomic library yielding a large number of clones that harbor photoreceptors or other agronomically important (intrinsic yield genes) traits is required.…”

Drought and Oxidative Stress in Flax (Linum usitatissimum L.) Entails Harnessing Non-Canonical Reference Gene for Precise Quantification of qRT-PCR Gene Expression

“…Over the last decade, the advent of new genomic tools has hastened research with the generation of enormous biological data [ 46 , 47 , 48 , 49 , 50 , 51 ] with high accuracy and efficiency [ 52 , 53 , 54 , 55 , 56 ]. These techniques have also enabled visualization of the impact of experiments/reactions in real-time.…”