Agriculture and Agri-Food Canada

About: Agriculture and Agri-Food Canada is a facility organization based out in Ottawa, Ontario, Canada. It is known for research contribution in the topics: Population & Soil water. The organization has 10921 authors who have published 21332 publications receiving 748193 citations. The organization is also known as: Department of Agriculture and Agri-Food.

Management of agricultural insects with physical control methods.

Abstract: Ideally, integrated pest management should rely on an array of tactics. In reality, the main technologies in use are synthetic pesticides. Because of well-documented problems with reliance on synthetic pesticides, viable alternatives are sorely needed. Physical controls can be classified as passive (e.g., trenches, fences, organic mulch, particle films, inert dusts, and oils), active (e.g., mechanical, polishing, pneumatic, impact, and thermal), and miscellaneous (e.g., cold storage, heated air, flaming, hot-water immersion). Some physical methods such as oils have been used successfully for preharvest treatments for decades. Another recently developed method for preharvest situations is particle films. As we move from production to the consumer, legal constraints restrict the number of options available. Consequently, several physical control methods are used in postharvest situations. Two noteworthy examples are the entoleter, an impacting machine used to crush all insect stages in flour, and hot-water immersion of mangoes, used to kill tephritid fruit fly immatures in fruit. The future of physical control methods will be influenced by sociolegal issues and by new developments in basic and applied research.

Homoeologous exchange is a major cause of gene presence/absence variation in the amphidiploid Brassica napus

Abstract: Homoeologous exchanges (HEs) have been shown to generate novel gene combinations and phenotypes in a range of polyploid species. Gene presence/absence variation (PAV) is also a major contributor to genetic diversity. In the present study we show that there is an association between these two events, particularly in recent Brassica napus synthetic accessions, and that these represent a novel source of genetic diversity, which can be captured for the improvement of this important crop species. By assembling the pangenome of B. napus, we show that 38% of the genes display PAV behaviour, with some of these variable genes predicted to be involved in important agronomic traits including flowering time, disease resistance, acyl lipid metabolism and glucosinolate metabolism. This study is a first and provides a detailed characterisation of the association between HEs and PAVs in B. napus at the pangenome level. This article is protected by copyright. All rights reserved.

The effect of overexpression of two Brassica CBF/DREB1-like transcription factors on photosynthetic capacity and freezing tolerance in Brassica napus.

Abstract: The effects of overexpression of two Brassica CBF/DREB1-like transcription factors (BNCBF5 and 17) in Brassica napus cv. Westar were studied. In addition to developing constitutive freezing tolerance and constitutively accumulating COR gene mRNAs, BNCBF5- and 17-overexpressing plants also accumulate moderate transcript levels of genes involved in photosynthesis and chloroplast development as identified by microarray and Northern analyses. These include GLK1- and GLK2-like transcription factors involved in chloroplast photosynthetic development, chloroplast stroma cyclophilin ROC4 (AtCYP20-3), beta-amylase and triose-P/Pi translocator. In parallel with these changes, increases in photosynthetic efficiency and capacity, pigment pool sizes, increased capacities of the Calvin cycle enzymes, and enzymes of starch and sucrose biosynthesis, as well as glycolysis and oxaloacetate/malate exchange are seen, suggesting that BNCBF overexpression has partially mimicked cold-induced photosynthetic acclimation constitutively. Taken together, these results suggest that BNCBF/DREB1 overexpression in Brassica not only resulted in increased constitutive freezing tolerance but also partially regulated chloroplast development to increase photochemical efficiency and photosynthetic capacity.

A New Locus for Early Maturity in Soybean

Abstract: The genetic model for maturity in soybean [Glycine max (L.) Merr.] is a series of near-isogenic lines, but they do not span the natural variation for early maturity. The objectives of this study were to determine if a single gene in OT98-17 controls early maturity and if this is a new locus. A cross was made between 'Maple Presto' and OT98-17, an early-maturing Maple Presto-derived backcross line. A total of 201 F 3 progeny rows from this population and Maple Presto were grown at Ottawa, ON, in 1999. In 2000, F 4 progeny rows were grown and 150 late-maturing and 51 early-maturing families were observed to fit a 3:1 ratio (n = 201, X 2 = 0.01, P = 0.90). The early-maturing allele was transferred to a 'Harosoy' background, and isolines were grown from 2002 to 2006 at Ottawa, ON. The isolines were 9 and 6 d earlier maturing in Maple Presto and Harosoy backgrounds, respectively. To determine the independence of this locus, simple sequence repeat molecular markers were used to identify three candidate regions. The gene E8 specifically mapped to linkage group C1 between Sat_404 and Satt136. No other maturity gene has been mapped to this region. The two other candidate regions were both related to maturity quantitative trait loci on molecular linkage group L and may be inadvertently selected along with early maturity. The gene symbol E8e8 has been assigned by the Soybean Genetics Committee. E8E8 results in later maturity and e8e8 results in early maturity. The earliest Harosoy maturity isoline is now rated as maturity group 000.