Marker-Assisted Pyramiding of Downy Mildew-Resistant Gene Ppa3 and Black Rot-Resistant Gene Xca1bo in Popular Early Cauliflower Variety Pusa Meghna

Cauliflower is an important extensively grown cool season vegetable in India. Black rot and downy mildew are major devastating diseases reducing yield and quality of the crop. To tackle these through host plant resistance, a marker-assisted backcross breeding method was followed to pyramid a black rot-resistant gene (Xca1bo) and a downy mildew-resistant gene (Ppa3) from donors BR-161 and BR-2, respectively, into the background of Pusa Meghna cauliflower cultivar. Marker-assisted backcross breeding was followed up to BC2 generation using SCAR marker ScOPO-04833 and SSR marker BoGMS0624 for black rot and downy mildew resistance genes in foreground selection, respectively. In background selection, at each stage of backcrossing, 47 parental polymorphic SSR markers were used. The graphical genotyping of the five two-gene (Xca1boXca1boPpa3Ppa3) homozygous BC2F2 plants showed an average recovery of 85.44% of the Pusa Meghna genome with highest genome recovery of 91.7%. The genome contribution of donor parents (BR-161 and BR-2) was 8.26 with 6.34% of residual heterozygousity. The backcross derived pyramided lines BC2F2:3-7-16 and BC2F2:3-7-33 showed high resistance to both the diseases and exhibited higher yield and vitamin C content as compared with recipient parent Pusa Meghna. It is, therefore, evident from this study that resistant genes can be introgressed successfully into a Pusa Meghna cultivar without any yield penalty, benefitting farmers with reduced input cost and consumers with chemical residue free produce. Besides, the pyramided lines carrying dominant resistant genes can be exploited in a hybridization programme to develop hybrid(s) in cauliflower.

Download Full-text

Modified backcross breeding method for rapid conversion of field corn line to shrunken2 (sh2) gene-based sweet corn line

Indian Journal of Genetics and Plant Breeding (The) ◽

10.31742/ijgpb.79.1.5 ◽

2019 ◽

Vol 79 (01) ◽

Author(s):

S. K. Jha ◽

N. K. Singh ◽

P. K. Agrawal

Keyword(s):

Sweet Corn ◽

Cost Effective ◽

Recurrent Parent ◽

Breeding Method ◽

Corn Hybrids ◽

Field Corn ◽

Recessive Mutant ◽

Backcross Breeding ◽

Skilled Person ◽

Marker Assisted Backcross Breeding

The non-availability of superior and diverse inbred parents is one of the major bottlenecks to develop high yielding sweet corn hybrids. The sh2, one of the promising recessive mutant alleles, has been used in sweet corn development however its transfer to superior field corn lines may require extra inbreeding to identify heterozygous carrier plants. The use of molecular markers linked with sh2 requires a well-equipped laboratory and skilled person to carry the marker assisted backcross breeding (MABB). Considering the above constraints, a modified backcross breeding method was used taking advantage of shrunken kernel of sweet corn for foreground selection coupled with phenotypic comparison with recurrent parent (RP). The BC1F1 plants were grown and plants having high phenotypic similarity with RP were selfed as well as backcrossed as pollen parent. The BC2F1 kernels of BC1F1 plants having high similarity with RP and segregation in BC1F2 kernels were harvested. The BC2F1 plants phenotypically most similar to recomment parameter (RP) were selfed and the shrunken kernels were selected from the segregating BC2F2 .The shrunken kernels were homozygous (sh2sh2) at Sh2 locus, which were validated upon inbreeding based on nonsegregating kernels in BC2F3 . The modified backcross method used is rapid, cost effective and can be used by maize breeder with limited resources for conversion as well diversification of sweet corn germplasm.

Download Full-text

Inheritance of Black Rot Resistance and Development of Molecular Marker Linked to Xcc Races 6 and 7 Resistance in Cabbage

Plants ◽

10.3390/plants10091940 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1940

Author(s):

Jeong-Eui Hong ◽

Khandker Shazia Afrin ◽

Md Abdur Rahim ◽

Hee-Jeong Jung ◽

Ill-Sup Nou

Keyword(s):

Molecular Marker ◽

Xanthomonas Campestris ◽

Black Rot ◽

Recessive Trait ◽

R Gene ◽

Nucleotide Polymorphisms ◽

F2 Population ◽

Yield And Quality ◽

Xanthomonas Campestris Pv Campestris

Black rot, caused by Xanthomonas campestris pv. campestris (Xcc), produces V-shaped chlorotic lesions on the leaves of cabbage (Brassica oleracea var. capitata L.), causing darkened veins and drastically reducing yield and quality. Of the 11 Xcc races identified, races 1, 4, and 6 are predominant globally. In the present study, we aimed to develop a molecular marker linked to black rot resistance against Xcc races 6 and 7. Crossed between black rot-resistant (‘SCNU-C-3470’) and -susceptible (‘SCNU-C-3328’) lines obtained 186 F2 plants. Resistance to Xcc race 6 segregated in a 3:1 (susceptible:resistant) ratio in the F2 population, which is consistent with a monogenic recessive trait. Nucleotide-binding site (NBS) leucine rich repeat (LRR)-encoding resistance (R) genes play a crucial role in plant defenses to various pathogens. The candidate R gene (Bol031422) located on chromosome C08, previously reported by our research group, was cloned and sequenced in resistant and susceptible cabbage lines. The R gene Bol031422 consisted of a single exon with a 3 bp insertion/deletions (InDels), a 292 bp polymorphism (an insertion in the exon of the resistant line relative to the susceptible line) and several single nucleotide polymorphisms (SNPs). Here, we developed the InDel marker BR6-InDel to assess linkage between variation at Bol031422 and resistance to Xcc races 6 and 7. This marker will help cabbage breeders develop cabbage cultivars resistant to Xcc races 6 and 7.

Download Full-text

Marker-Assisted Backcross Breeding for Improvement of Submergence Tolerance and Grain Yield in the Popular Rice Variety ‘Maudamani’

Agronomy ◽

10.3390/agronomy11071263 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1263

Author(s):

Elssa Pandit ◽

Swapnil Pawar ◽

Saumya Ranjan Barik ◽

Shakti Prakash Mohanty ◽

Jitendriya Meher ◽

...

Keyword(s):

Grain Yield ◽

Rice Variety ◽

Yield Component ◽

Submergence Tolerance ◽

Breeding Method ◽

Submergence Stress ◽

Backcross Breeding ◽

Grain Width ◽

Marker Assisted Backcross Breeding ◽

Recipient Parent

Submergence stress due to flash floods reduces rice yield drastically in sensitive varieties. Maudamani is a high yielding popular rice variety but is highly susceptible to submergence stress. The selection of progenies carrying Sub1 and GW5 (wide-grain) enhanced the submergence stress tolerance and grain yield of theMaudamani variety by following the marker-assisted backcross breeding method. Foreground screening detected 14 BC1F1, 17 BC2F1, and 12 BC3F1 backcross progenies that carried the target QTLs for submergence tolerance and grain width. Background screening was performed in the progenies carrying the target QTL and enhanced the recovery of a recipient parent’s genome by upto 96.875% in the BC3 pyramided line. The BC3F1 plant containing the highest recipient parent genome content and the target QTLs was self-pollinated. In BC3F2 generation, the target QTLs the Sub1 and GW5 (wide-grain) alleles and recipient parent’s yield component QTL OsSPL14 were tracked for homozygous states in the progenies. Seven pyramided lines showed tolerance to submergence for 14 days and higher grain yield than both the parents. The pyramided lines were similar to the recipient parent for the majority of the studied morphological and quality traits. The pyramided lines are useful as cultivars and can serve as potential donors for transfer of Sub1, OsSPL14, Gn1a, GW5 (wide-grain), and SCM2 QTLs.

Download Full-text

Introgression of QTLs determining sorghum downy mildew (SDM) resistance into elite maize line UMI 79 through marker-assisted backcross breeding (MABC)

Australasian Plant Pathology ◽

10.1007/s13313-020-00686-9 ◽

2020 ◽

Vol 49 (2) ◽

pp. 159-165 ◽

Cited By ~ 1

Author(s):

K. Sumathi ◽

K. N. Ganesan ◽

P. Aarthi ◽

V. Sruthymenon ◽

S. Devasree ◽

...

Keyword(s):

Downy Mildew ◽

Maize Line ◽

Sorghum Downy Mildew ◽

Backcross Breeding ◽

Marker Assisted Backcross Breeding

Download Full-text

The effect of time of cutting on yield and the quality of the hop hybrid varieties Harmonie, Rubín and Agnus

Plant Soil and Environment ◽

10.17221/187/2010-pse ◽

2010 ◽

Vol 56 (No. 12) ◽

pp. 564-569 ◽

Cited By ~ 1

Author(s):

K. Krofta ◽

J. Ježek

Keyword(s):

Downy Mildew ◽

Acid Content ◽

Weather Conditions ◽

Experimental Period ◽

Measured Data ◽

Statistical Relationship ◽

Average Yield ◽

Yield And Quality ◽

Mechanized Cutting

The influence of mechanized cutting time on the yield and quality of hops was studied for three years (2007, 2008 and 2009) in three Czech hybrid varieties Harmonie, Rubín and Agnus. The cutting term classified as 'early' was carried out at the turn of March and April. Further cutting dates were made at intervals of 7–10 days and they were classified as 'middle' and 'late' ones. Yield and contents of alpha acids were evaluated during the machine harvest. The measured data revealed no statistical relationship between term of cutting, alpha acid content and yield in any of the tested cultivars. However, during the experimental period considerable inter-annual differences were observed, especially in the yield. Average yield in the range of 2.0–2.5 t/ha in the period 2007–2008 decreased to 1.2–1.9 t/ha in 2009 due to downy mildew attack. On the basis of the obtained data it can be recommended to cut the hybrid varieties Harmonie, Rubín and Agnus in the first ten days of April, taking into account other factors such as age and the location of hop garden and current weather conditions.

Download Full-text