The effect of cold and heat treatments on the anther culture response of diverse rye genotypes

The reduction of saturated fats in canola oil has recently been promoted as a goal for breeders for commercial and human health benefits. Currently, saturated fatty acids in Canadian produced canola oil are above the 7% level, and the objective of this study was to generate canola lines with reduced major saturates (palmitic and stearic), by several percent. Mutant embryos generated from direct ultraviolet radiation mutagenesis of microspores in vitro were subjected to heat during the maturation stage. Heat artificially elevated the saturate levels in developing mutant embryos, allowing efficient identification of those with reduced saturates within the expanded range using HPLC fatty acid analysis of the embryo cotyledons. Mutagenesis produced embryos with fatty acids altered in both directions. Major saturate levels in the cotyledons of heat-treated mutant embryos ranged from 3.3 to 16.4% (heated control ca. 6–9%) and 1.3–10% (heated control ca. 2–4%) for palmitic and stearic fatty acids, respectively. Doubled haploid seed derived from embryos grown at normal temperatures confirmed the reduction of major saturates. HPLC fatty acid analysis of DH seed identified saturate levels ranging from 3.9 to 6.5% (control ca. 5.5%) and 0.9–2.7% (control ca. 1.7%) for palmitic and stearic fatty acids, respectively. Various doubled haploids were identified with major saturate levels below 5.5%. Concomitant positive changes in the unsaturated fatty acids (18:1, 18:2, 18:3) among the mutant lines are also discussed.     

Feeding sows with high fibre diet around farrowing and early lactation: impact on intestinal activity, energy balance related parameters and litter performance

The effects of fibre in diets for periparturient sows are poorly documented. Three weeks before farrowing, 41 sows (LACT) were fed a diet containing 3.8% crude fibre. Other 40 sows (FIBRE) received a diet containing 7% crude fibre. We estimated the intestinal activity of the sows with a daily qualitative evaluation of their faeces. The FIBRE group had a qualitative faeces score value of 2.1 ± 1.3 and the LACT group had a value of 1.2 ± 1.1 (P < 0.001). Individual daily water consumption was higher in the FIBRE group than in the LACT group (P < 0.001). Piglet weight gain at day 5 was higher in the FIBRE group (P < 0.05). The energy balance related parameters did not differ between the treatments.Concluding, diets containing more fibre can be successfully used around farrowing reducing prolonged constipation of sows with no negative effect on their energy balance related parameters.     

Boron in forest trees and forest ecosystems

This review critically examines the role of boron (B) in forests in view of recent findings on B nutrition and the continuing occurrence of B deficiency. Many perceptions about the role of B in plants and its uptake and mobility have been altered since the last review on B in forest trees in 1990. Now there is evidence for a fundamental role of B in the formation of the pectic structure in primary cell walls in plants, and further roles in membrane function are being explored. In plants, channel-mediated B uptake, active B uptake and B uptake by mycorrhizas have been shown, B transporters have been identified, and B retranslocation has been shown. We explore these findings and their consequences on forest trees and on ecosystems that they dominate. Particular emphasis is placed on B retranslocation and B in mycorrhizal symbiosis, given their importance in trees.     

Tagging the dwarfing gene <Emphasis Type="Italic">Ddw1</Emphasis> in a rye population derived from doubled haploid parents

To prevent lodging and sprouting damage in rye, a dominant dwarfing gene, Ddw1, has been incorporated into breeding lines to reduce plant height in Finland. However, the inability to identify heterozygous plants makes it difficult to purify breeding lines. Doubled haploidy (EM-1 × Voima) and bulked segregant analysis were used to search for an efficient PCR-based tool to identify homozygous short plants. In addition, SNP (single nucleotide polymorphism) markers were created from the endosperm-specific β-amylase gene and the microsatellite locus REMS1218 expressed in rye and known to be located near Ddw1. The best marker was a combination of the microsatellite REMS1218 and the SNP created from it, located 13 cM from the QTL corresponding to Ddw1. However, for a rye breeder, the SNP alone is an adequate tool to identify plants homozygous for the EM-1 allele and it can be used in selection for the desirable growth habit in rye.     

Boron nutrition affects the carbon metabolism of silver birch seedlings

Boron (B) is an essential micronutrient whose deficiency is common both in agriculture and in silviculture. Boron deficiency impairs the growth of plants and affects many metabolic processes like carbohydrate metabolism. Boron deficiency and also excess B may decrease the sink demand by decreasing the growth and sugar transport which may lead to the accumulation of carbohydrates and down-regulation of photosynthesis. In this study, we investigated the effects of B nutrition on the soluble and storage carbohydrate concentrations of summer leaves and autumn buds in a deciduous tree species, Betula pendula Roth. In addition, we investigated the changes in the pools of condensed tannins between summer and autumn harvests. One-year-old birch seedlings were fertilized with a complete nutrient solution containing three different levels of B: 0, 30 and 100% of the standard level for complete nutrient solution. Half of the seedlings were harvested after summer period and another half when leaves abscised. The highest B fertilization level (B100) caused an accumulation of starch and a decrease in the concentrations of hexoses (glucose and fructose) in summer leaves, whereas in the B0 seedlings, hexoses (mainly glucose) accumulated and starch decreased. These changes in carbohydrate concentrations might be related to the changes in the sink demand since the autumn growth was the smallest for the B100 seedlings and largest for the B30 seedlings that did not accumulate carbohydrates. The autumn buds of B30 seedlings contained the lowest levels of glucose, glycerol, raffinose and total polyols, which was probably due to the dilution effect of the deposition of other substances like phenols. Condensed tannins accumulated in high amounts in the birch stems during the hardening of seedlings and the largest accumulation was detected in the B30 treatment. Our results suggest that B nutrition of birch seedlings affects the carbohydrate and phenol metabolism and may play an important role in the hardening process of the seedlings.     

Molecular markers and doubled haploids in European plant breeding programmes

The breeding companies and laboratories involved in this article cover a wide range of crops grown in the temperate climate zone: small grain cereals, oilseed crops, forage crops, turf, vegetables and potato. Speed and efficiency are becoming increasingly important in variety breeding and doubled haploids (DH) and genetic markers are important biotechnological tools to accelerate materials to market. Collaborative research between universities, research institutions and breeding companies has resulted in the routine use of DH technology and molecular markers in practical breeding of barley, wheat and rapeseed. DH populations have been established not only for barley, wheat and rapeseed, but for rye, oat and triticale, where DH technology is less developed. A driver here is the value of the crop e.g. although wheat is less responsive to DH production the value of the end product makes the effort worthwhile. Simple and rapid DNA extraction methods used in high-throughput marker assisted selection (MAS) systems are essential for routine use of markers. MAS is used both to monitor the presence of genes of interest and also to monitor the genetic background. DH technology in forage, turf and vegetables is still in progress and the practical use of markers in all crops is limited by access to trait linked markers. Collaboration and technology transfer with universities, research institutions and breeding companies is essential for the improvement of both DH protocols in recalcitrant crops and marker technology in all crops.