Genetic variation and stability of agronomic and quality traits in soybean varieties grown in western Canada between 2013 and 2018

Non-Peer ReviewedSoybean is one of the major crops of the world, but relatively new to western Canada, especially areas west of Morden, Manitoba. Expansion of soybean production to these Canadian Prairies has been slow due to a lack of adapted very-early maturing cultivars. Evaluation of stability and adaptability of a genotype to a broad range of environments is beneficial to recommend cultivars for known conditions of cultivation. Diverse soybean varieties were evaluated over multiple locations in Saskatchewan for six years (2013-2018). Significant effects of genotype, environment, and genotype and environment interaction were detected for phenology, agronomic and quality traits. Broad sense heritability estimates are medium to high for most of these traits in many site-years. Varieties with good performance stability for yield, quality and days to maturity were detected over the study period. Results from this study suggests some recommendations for soybean breeding and expansion in western Canada

Mapping QTL associated with yield and yield components and Ascochyta blight in chickpea

Non-Peer ReviewedChickpea (Cicer arietinum L.) is the third important legume crop in production among the world pulse crops. A better understanding of the genetic basis of yield and disease traits and their association with flowering time could contribute to their use in the breeding strategies of the crop in the Canadian Prairies. The objective of this study was to evaluate a set of Recombinant Inbred Lines (RILs) of chickpea for yield and disease traits and to locate Quantitative Trait Loci (QTL) associated with these traits. This study used a RIL population derived from across between ICCV 96029 (a desi market class, an extra early maturing, highly susceptible to ascochyta blight and CDC Frontier (a kabuli market class, late maturing, moderately resistant to ascochyta blight. A population consisting of 92 RILs together with the 2 parents were grown in a field at Elrose, Saskatchewan in 2011 in a micro plot with 2 replications. Measurements on agronomic traits were made on an individual plant basis and the means of five plants were used for analysis. Plants were air-dried at 35°C for 48 h before measuring the above-ground biomass. Traits measured were grain yield (in gm /plant), above ground biomass (in g/ plant), number of grains /plant, number of pods/ plant, and 1000 seed weight. Harvest index (HI) = grain weight/total above ground dry weight. The result indicated that, there was significant difference in plant height (in cm), number of seeds /plant, number of seeds/pod, 1000 seeds weight (in gm/plant) and Harvest Index (%). The same lines were evaluated in the greenhouse for Ascochyta blight reaction and in the growth chambers for their flowering responses to different photoperiod. Mapping of QTL will be performed on the line mean data for single years of the field observation and for different photoperiod treatments in the growth chamber

Rapid introgression of common bacterial blight resistance genes into dry bean elite varieties by marker-assisted backcrossing

Non-Peer Reviewe

Iron bioavailability in low-phytate pea

Non-Peer ReviewedPhytate is the main storage form of phosphorus in the seeds of most crops. Phytate is not well digested by monogastrics and it chelates iron, zinc and some other micronutrients. To increase the nutritional value of pea seeds, two low phytate lines (1-150-81 and 1-2347-144) were developed from CDC Bronco in previous research. In this study, an in vitro digestion/Caco-2 cell culture bioassay was used to simulate the iron absorption of peas in humans, as the cell line originated from human colon adenocarcinoma cells. The iron bioavailability of the two low-phytate lines was 1.4 to 1.9 times higher than that of three normal phytate varieties, while having the same total iron concentration. In vivo studies were used to evaluate iron absorption of chickens fed low phytate and normal phytate pea diets. The diets containing the two low-phytate pea lines had no significant effect on chicken body weight and hemoglobin level, compared with the diets containing normal phytate pea cultivars, however, iron deficiency was suspected in all diets used

Moving pulse crop breeding into the 21st century

Non-Peer Reviewe

Iron bioavailability in low phytate pea

Non-Peer ReviewedThe objectives of this study are to determine the effect of genotype and environment on iron bioavailability in a set of five pea varieties differing in phytate concentration using the in vitro digestion/Caco-2 human cell assay (Glahn 2009), to determine whether iron bioavailability in field pea is heritable by evaluating recombinant inbred lines (RILs) differing in phytate concentration using in vitro digestion/Caco-2 human cell assay, and to determine the effect of the pea low phytate trait on chicken performance and iron bioavailability in chicken. In a previous study, two low phytate pea lines (1-2347-144 and 1-150-81) were developed from CDC Bronco at the Crop Development Centre, University of Saskatchewan (Warkentin et al. 2012). As a powerful chelator of iron, phytate can reduce the iron bioavailability in diets. The low phytate peas may have increased iron bioavailability compared to the normal phytate peas. In the first objective of this project, the iron bioavailability of pea seeds of the two low phytate lines, their parent CDC Bronco and two other popular pea varieties in western Canada (CDC Meadow and CDC Golden), derived from 3 replicate field experiments conducted in 2009 and 2010 at SPG (Saskatchewan Pulse Growers land), Outlook and Rosthern, were assessed using the in vitro digestion/Caco-2 cell culture. The result shows that the iron bioavailability of the two low phytate lines is significantly higher than the other three normal phytate varieties, although their iron concentrations have not significant difference. The low phytate line 1-2347-144 and CDC Meadow were crossed to develop RILs

Effects of hatching timing on red-eyed treefrog tadpoles: relative vulnerability varies among predators but not with hatchling age-structure, growth varies with the presence of more vulnerable tadpoles [poster]

In Gamboa, Panama, undisturbed red-eyed treefrog embryos typically hatch at age 6 days, but they can hatch as early as 4 days if attacked by egg predators. Early hatchlings are less developed and more vulnerable to predatory shrimp and fish. Here we assess the effect of hatching timing on risk of predation by three common insects, with different foraging styles, that prey on red-eyed treefrog larvae. Further, we examine whether the consequences of hatching early vary with the presence of later-hatched tadpoles. We induced hatching at 4 and 6 days and exposed tadpoles to giant water bugs or aeshnid or libellulid dragonfly larvae over 24 hrs, quantifying tadpole behavior and mortality. We used substitutive designs with three treatments: early hatched, late hatched and mixed hatching ages. In no case did presence of the other age class alter mortality. Hatching age did not affect libelullid predation, which was low in both cases. Early-hatched tadpoles had higher mortality than late hatchlings with water bugs, which move throughout the water column. In contrast, early hatchlings had lower mortality than late hatchlings with aeshnids, which cue strongly on movement. Late-hatched tadpoles were more active than early hatchlings, and movement was reduced in the presence of aeshnids. Combining across this and previously published studies, early hatchlings are more vulnerable than late hatchlings to most (3/5) predators. Variation in relative, age-specific hatchling vulnerability to predators with different foraging styles is consistent with developmental changes in tadpole behavior

Early post-operative thrombosis of the prosthetic mitral valve in patient with heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is one of the most common immune-mediated adverse drug reactions, with frequencies as high as 2-3% for certain groups of post-cardiac surgery patients. We report on an 50-year-old woman with early post-operative thrombosis of the prosthetic mitral valve due to heparin-induced thrombocytopenia. Non-invasive imaging (two-dimensional transesophageal echocardiography; 2D-TEE) allowed the exact localisation of thrombotic masses and revealed the increase of the mean diastolic mitral gradient. The HIT diagnosis was proved by the clinical scoring system, and with the identification of heparin platelet factor 4-induced antibodies. After the withdrawal of LMWH therapy and the start of intravenous lepirudin treatment, the patient's medical condition improved continuously. Follow-up echocardiography showed a step-wise decrease in the severity of the mean diastolic mitral valve gradient and a complete resolution of thrombus formations. Perhaps we may remind ourselves that, whilst HIT is one of the most common immune-mediated adverse drug reactions for certain groups of post-cardiac surgery patients, it can be managed successfully. We would also stress the importance of serial 2D-TEE examinations in the early post-operative period

The Cost of Hatching Early: Vulnerability and Exposure to Predators [poster]

Arboreal red-eyed treefrog embryos can hatch prematurely in response to egg predators. Induced early hatchlings face aquatic predators when less developed and for longer than do later hatchlings; both factors may alter survival through the high-risk early larval period. Prior work focused on developmental effects of induced hatching. In 24 h trials, less developed hatchlings were more vulnerable to three aquatic predators (shrimp, fish, water bugs) but had similar or better survival than full-term hatchlings with libellulid and aeschnid dragonfly nymphs. However, it is unknown how developmental effects and duration of exposure to predators combine to create the net effect of early hatching. Here we measured costs of early hatching over a 72 h period, from first hatching competence past peak spontaneous hatching. Embryos hatched at age 4 or 6 days were exposed to water bugs, aeshnids, or libellulids. Early-hatched tadpoles suffered higher mortality than late hatchlings with all three predators. The longer exposure of early hatchlings to aquatic predators reversed their initial phenotypic advantage with aeshnids and revealed a cost of early hatching with libellulids where none was apparent from phenotypes alone. In other experiments, early-hatched tadpoles reared without predators grew more quickly than those reared with predators cues, which grew more quickly than age-matched embryos, revealing phenotypic effects of both predator cues and the egg vs. aquatic environment. Nonetheless, any potential benefits of predator-induced phenotypes on tadpole survival were insufficient to compensate for the increased duration of predator exposure that is a consequence of hatching early. From the Conference Program at http://www.sicb.org/meetings/2011/schedule/abstractdetails.php3?id=23

Genomics-Integrated Breeding for Carotenoids and Folates in Staple Cereal Grains to Reduce Malnutrition

Globally, two billion people suffer from micronutrient deficiencies. Cereal grains provide more than 50% of the daily requirement of calories in human diets, but they often fail to provide adequate essential minerals and vitamins. Cereal crop production in developing countries achieved remarkable yield gains through the efforts of the Green Revolution (117% in rice, 30% in wheat, 530% in maize, and 188% in pearl millet). However, modern varieties are often deficient in essential micronutrients compared to traditional varieties and land races. Breeding for nutritional quality in staple cereals is a challenging task; however, biofortification initiatives combined with genomic tools increase the feasibility. Current biofortification breeding activities include improving rice (for zinc), wheat (for zinc), maize (for provitamin A), and pearl millet (for iron and zinc). Biofortification is a sustainable approach to enrich staple cereals with provitamin A, carotenoids, and folates. Significant genetic variation has been found for provitamin A (96–850 mg and 12–1780 mg in 100 g in wheat and maize, respectively), carotenoids (558–6730 mg in maize), and folates in rice (11–51 mg) and wheat (32.3–89.1 mg) in 100 g. This indicates the prospects for biofortification breeding. Several QTLs associated with carotenoids and folates have been identified in major cereals, and the most promising of these are presented here. Breeding for essential nutrition should be a core objective of next-generation crop breeding. This review synthesizes the available literature on folates, provitamin A, and carotenoids in rice, wheat, maize, and pearl millet, including genetic variation, trait discovery, QTL identification, gene introgressions, and the strategy of genomics-assisted biofortification for these traits. Recent evidence shows that genomics-assisted breeding for grain nutrition in rice, wheat, maize, and pearl millet crops have good potential to aid in the alleviation of micronutrient malnutrition in many developing countries