Page 260 - PC2019 Program & Proceedings

PLANT CANADA 2019

P93. Genome-wide analysis of thaumatin-like proteins in cereals
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Iqbal, I. ; R. Tripathi; O. Wilkins; J. Singh
McGill University

Beta-glucan is the major non-starch dietary fiber present in the barley grains. Barley with low beta-glucan
is a desirable trait for the malting barley breeding and brewing industry. However, varieties with higher
amounts of beta-glucan are tailored for feed and food purpose as higher levels of beta-glucan causes
hindrance during malting. Recently, a barley Thaumatin-Like Protein (TLP), HvTLP8 located on
chromosome 4H has been reported for its interaction with beta-glucan. To further characterize TLPgene
family in cereals, we identified 19, 37, 28 and 35 TLP genes from the barley,
rice, Brachypodium and sorghum genomes using the TLP domain as a query. Two novel cysteine-
rich genes on chromosome 3H, HvTLP14 andHvTLP17 were identified which possess carbohydrate-
binding motif. We also observed the transcript abundance of HvTLPs in germinating grains at 16, 48 and
96 hrs of imbibition in barley malt and feed varieties. Expression of HvTLP14 and HvTLP17 was found to
be higher in malting and lower in feed varieties. We are exploring the role of these carbohydrate binding
proteins for their role during malting and developing a functional marker (genetic and ELISA-based
biochemical) for the selection of superior malting varieties.

Irfan Iqbal (Irfan.iqbal@mail.mcgill.ca)

P94. Agronomic performance and nitrogen fixation of heirloom and conventional dry bean varieties
under low-nitrogen field conditions
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2
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1
1
1
3
Wilker, J ; A. Navabi ; I. Rajcan ; F. Marsolais ; B. Hill ; D. Torkamaneh ; P. Pauls
1 University of Guelph
2 Agriculture Agri-food Canada
3 Université Laval
Dry bean (Phaseolus vulgaris) is a diverse species grown worldwide as an important source of protein
and income. Beans engage in symbiotic nitrogen fixation (SNF) with rhizobia, but are poor nitrogen
fixers among legumes. Whereas heirloom varieties developed under natural environmental conditions,
conventional varieties are developed using modern practices including the use of SNF-suppressing N
fertilizer potentially leading to the loss of SNF efficiency. Here we test the hypothesis that heirloom
beans have a greater capacity for SNF than conventionally-bred bean varieties and examine whether they
could be useful germplasm sources to improve this trait. We examined SNF capacity under low-N field
conditions for a 42-genotype heirloom-conventional panel (HCP). The HCP was genotyped to investigate
genetic relatedness and genepool membership. Three field trials were conducted in Ontario, Canada from
2014-15 and agronomic and seed composition traits were measured. Significant variation for SNF was
found. Overall, heirloom genotypes did not fix significantly more nitrogen than conventional genotypes.
However, five heirloom genotypes obtained > 60 % of their nitrogen through SNF. Grain yield was not
significantly different between heirloom and conventional categories suggesting that using heirloom
genotypes in a modern breeding program would not negatively impact yield. SNF was significantly
higher among Middle American (MA) genotypes than among Andean (A) genotypes. Heirloom
genotypes are a promising source of genetics to improve SNF in modern bean varieties.

Jennifer Wilker (jwilker@uoguelph.ca)

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