Tocopherol Content and Fatty Acid Distribution of Peas (Pisum sativum L.)

Mapping QTL associated with partial resistance to Aphanomyces root rot in pea (Pisum sativum L.) using a 13.2 K SNP array and SSR markers

KEY MESSAGE

A stable and major QTL, which mapped to an approximately 20.0 cM region on pea chromosome 4, was identified as the most consistent region conferring partial resistance to Aphanomyces euteiches. Aphanomyces root rot (ARR), caused by Aphanomyces euteiches Drechs., is a destructive soilborne disease of field pea (Pisum Sativum L.). No completely resistant pea germplasm is available, and current ARR management strategies rely on partial resistance and fungicidal seed treatments. In this study, an F8 recombinant inbred line population of 135 individuals from the cross 'Reward' (susceptible) × '00-2067' (tolerant) was evaluated for reaction to ARR under greenhouse conditions with the A. euteiches isolate Ae-MDCR1 and over 2 years in a field nursery in Morden, Manitoba. Root rot severity, foliar weight, plant vigor and height were used as estimates of tolerance to ARR. Genotyping was conducted with a 13.2 K single-nucleotide polymorphism (SNP) array and 222 simple sequence repeat (SSR) markers. Statistical analyses of the phenotypic data indicated significant (P < 0.001) genotypic effects and significant G × E interactions (P < 0.05) in all experiments. After filtering, 3050 (23.1%) of the SNP and 30 (13.5%) of the SSR markers were retained for linkage analysis, which distributed 2999 (2978 SNP + 21 SSR) of the markers onto nine linkage groups representing the seven chromosomes of pea. Mapping of quantitative trait loci (QTL) identified 8 major-effect (R2 > 20%), 13 moderate-effect (10% < R2 < 20%) effect and 6 minor-effect (R2 < 10%) QTL. A genomic region on chromosome 4, delimited by the SNP markers PsCam037549_22628_1642 and PsCam026054_14999_2864, was identified as the most consistent region responsible for partial resistance to A. euteiches isolate Ae-MDCR1. Other genomic regions important for resistance were of the order chromosome 5, 6 and 7.

Meat quality of buffalo young bulls fed faba bean as protein source

Sixteen Italian Mediterranean Buffalo young bulls were divided into two groups fed isoprotein and isoenergy diets and only differing for protein source of concentrate: faba bean (FB) vs soybean (SB). Animals were slaughtered at 350 kg BW. Meat from FB group showed significantly lower fat, protein, cholesterol and saturated fatty acids than SB group. Significant differences were also found between the three muscles analysed [Longissimus thoracis (LT), Semitendinosus (ST) and Iliopsoas plus Psoas minor (IP)]. ST showed the most favourable fatty acids profile: lower SFA, higher PUFA, MUFA, ω-3, ω-6, CLA and, consequently, lower values for both atherogenic and thrombogenic indexes. Results showed that faba bean can be used as a protein source alternative to soybean in the diet of young buffalo bulls for the production of high quality meat.

Agronomical factors influencing the legumin/vicilin ratio in pea (Pisum sativum L.) seeds

BACKGROUND

Many research studies have investigated the impact of agronomical factors on the protein content of pea (Pisum sativum). This study aimed to establish if a correlation exists between protein content and legumin/vicilin (L/V) ratio in pea seeds and to identify agronomical factors that have an impact on this ratio.

RESULTS

The L/V ratio was positively correlated with protein content (r = 0.58, P ≤ 0.01), but no linear regression was applicable (adjusted R(2) = 0.31). Both variety and cultivation year had a highly significant effect on the ratio (P < 0.001). The interaction between these two factors was also highly significant (P < 0.001), some varieties being less sensitive to climatic conditions than others. Cultivation location had a highly significant effect (P < 0.01). There was no interaction between variety and location. Seeding density had a highly significant effect on the ratio (P < 0.01), with a saturation effect above 60 seeds m(-2).

CONCLUSION

Further studies should establish if a linear regression model can be applied to pea varieties independently. Varieties with a stable L/V ratio can prove to be useful in the food industry. Other agronomical factors (soil type and seeding density) should be considered for the production of pea seeds with a specific L/V ratio.

Legumes are valuable sources of tocopherols

Grain legumes contain numerous phytochemicals useful for their nutritional or nutraceutical properties, such as tocopherols, involved in the prevention of cardiovascular disease and eye pathologies. In this work, tocopherols were quantified in soybean, chickpea, lentil, pea, common bean, broad bean, and three lupin species. In all samples, the gamma congener was the most abundant tocopherol, followed by minor quantities of alpha-tocopherol (with the exception of common bean lacking in this congener) and delta-tocopherol (with the exception of Lupinus angustifolius and Lupinus mutabilis). Beta-tocopherol and tocotrienols were never detected. Some samples of soybean, pea, white lupin and chickpea contained over 10mg/100g seeds of total tocopherols. In order to estimate the nutritional value, the vitamin E activity was calculated. Chickpea, soybean and, to a lesser extent, lupin, broad bean and pea may contribute in a relevant way to the daily intake of this vitamin.

Relative changes in tocopherols, isoflavones, total phenolic content, and antioxidative activity in soybean seeds at different reproductive stages

Immature seeds of soybean are becoming increasingly popular as a snack/vegetable to harness the health benefits of soybean. They are shelled from the immature pods picked from the mother plant at different reproductive stages. Information concerning changes in antioxidant constituents and antioxidant capacity during reproductive phases of soybean seeds is scarce. The aim of the present study was to determine whether immature seeds picked at different reproductive stages differ in tocopherol, isoflavone, total phenolic contents, free radical scavenging activity, and total antioxidative capacity. Seeds shelled from the soybean pods picked at three reproductive stages (R5, R6, and R7) as well as at full maturity were subjected to high-performance liquid chromatography analyses for tocopherol and isoflavone contents. Significantly higher values (P<0.05) were observed for tocopherols and isoflavones in immature seeds picked at late reproductive stages. At the first reproductive stage, that is, R5 stage, delta-tocopherol was the predominant form of tocopherol, whereas in subsequent reproductive stages as well as at complete maturity stage, the gamma-isomer contributed maximum proportion to the total tocopherol content. Genistein was, in general, the major form of isoflavone at all reproductive stages. Reduction in free radical scavenging activity, total antioxidant capacity, and total phenolic content in late-picked seeds concomitant with increased concentration of tocopherol and isoflavone isomers was observed. The results show that bioactive constituents other than isoflavones and tocopherols may decline with the advancement of maturity.