Physiology

Overview

The objectives of the Pulse Research Group Physiology Program is to investigate whole plant and field responses of crops, particularly pulse crops, to nutrient, water and weather.  To understand and improve yield formation in pulse crops in a warming climate.  To investigate and improve nitrogen fixation and nitrogen partitioning in pulse crop growth and yield.

Plan to achieve objectives

Crop Physiology is a modest sized program with one program leader (Dr Rosalind Bueckert), a technician and two graduate students.  Rosalind Bueckert has a collaborative project with Dr Lynne Seymour, University of Georgia, which investigates weather variables on yield response for historic yield records across the prairies.  Rosalind Bueckert, in collaboration with Pea Breeding, is also analyzing the pea variety trials for yield response to warmer weather patterns.  Graduate student Hossein Zakeri is investigating nitrogen partitioning in lentil, and graduate student Adil Choudhry is investigating various management strategies to control indeterminate growth in lentil.  Both students work on a collaborative project with Lentil Breeding and Soil Science.  Janet Pritchard is currently screening a commercial rhizobia collection to select for earlier nitrogen fixing combinations of inoculant and lentil.  She is also working with Rosalind Bueckert on screening 15 genotypes of faba bean to measure nitrogen accumulation and to develop a method to select for high nitrogen accumulating types (in collaboration with Faba Breeding).

Expected Outcomes

We expect to characterize the yield response of pea to temperature and rainfall, and to predict sensitive growth stages and yield response when certain weather occurs during specific stages.  We can identify what needs to be improved in future pea cultivars to better withstand a changing climate.  For lentil, we will have characterized nitrogen accumulation and nitrogen-related growth responses in this indeterminate crop in inoculated, non-inoculated or fertilized environments, so growers can manage crop growth for better earliness and yield.   The faba project outcome is two-fold: to provide information on the amount of nitrogen in faba stubble which will be available to succeeding crops in a rotation, and to screen for high nitrogen fixing and high nitrogen accumulating genotypes so Faba Breeding can supply good nitrogen accumulating varieties.

Projects
2018
<p>Lentil breeders sometimes use exotic germplasm to broaden the genetic base and introduce desirable traits to elite cultivars. However, offsprings from these wide crosses often adapt poorly in the short growing season of western Canada. Identifying regions in the lentil genome that influences traits such as flowering time and maturity will help develop markers for breeders to effectively predict the adaption characteristics without trialing the plants in the field.&nbsp; To achieve this objective, we are phenotyping and genotyping several RILs that are developed from crosses of adapted and exotic germplasm.</p>
2018
<p>Lentils are known as low-fat, nutrient-dense foods with many health benefits. Part of these beneficial properties have been attributed to their colorful content, namely carotenoids, anthocyanins and other flavonoid pigments. Carotenoids are responsible for red, orange and yellow colors in plants, and they are of major importance in human diet as precursors of vitamin A, antioxidants, and for their anticancer properties. In lentils, differences in carotenoid concentration may explain the differences in cotyledon colors, which can be red, yellow or green. Anthocyanins are responsible for orange, red, and purple colors in plants, and have also been shown to reduce the risks of cardiovascular diseases and cancer. Lentil seed coat colors can be green, brown, tan or black, with or without patterns. These differences might be explained by differences in anthocyanin, pro-anthocyanidin and carotenoid concentrations. We are working on characterizing the effects of the environment on these pigments in both the cotyledon and the seed coat, and the genetics underlying color determination. We are also interested in developing automated solutions to precisely and efficiently determine color variation and diversity in lentil cotyledon and seed coat.&nbsp;</p>
2018
<p>Growth habit, seed size and shattering are some of the most significant agronomic traits involved in the domestication process. Wild lentils tend to be prostrate while cultivated ones need to be upright, especially for disease avoidance and mechanical harvesting. Wild lentil seeds are tiny while cultivated ones tend to be slightly to significantly larger, depending on market class.&nbsp; Shattering is an effective method of seed dispersal in the wild but leads to terrible yields under crop conditions!</p><p>We are phenotyping and genotyping several interspecific RIL populations with a view to tagging regions of the lentil genome associated with the shift from a wild phenotype to a more farmer-friendly one. For phenotyping purposes, we are developing an imaging system (Nielsen, K et al, manuscript in preparation) to characterize more accurately and automatically traits such as leaf surface area and biomass.</p>
2017 to 2018
<p>Today, superior Canadian lentil cultivars are expected to grow well in our northern growing conditions while being resilient to various abiotic and biotic stresses.&nbsp; &nbsp;The breeders achieve this by using diverse materials in their crosses, but need to ensure that offspring from these crosses can flower and mature at the right time in Saskatchewan. If we could predict flowering and maturity traits in lentil effectively using genetic markers, we will then be able to devote more valuable resources to evaluating other important traits such as yield, disease resistance and seed quality.</p><p>To develop genetic markers, we are studying a RIL population from a cross between a South Asian line and a Canadian line.&nbsp; Under Saskatchewan field conditions, this population segregates for days to flowering and other traits related to plant development and maturity. The population has been genotyped and we will identify genetic regions influencing flowering time and maturity traits and turn over markers for these traits to lentil&nbsp; breeders.</p>
2017
<p>Nitrogen fixation is a symbiotic relation between legumes and Rhizobium that allows the bacteria to convert atmospheric nitrogen to other molecules (like ammonia) for the plant, and the plant to provide the bacteria with carbohydrates in exchange.&nbsp; We now know that this process provides many great benefits to the health of our soil and crops.</p><p>The effectiveness/intensity of the nitrogen fixation process is dependent on both the bacteria and the legume plant under specific environment.&nbsp; Wild species have contributed to the lentil crop with tolerance and resistance to biotic and abiotic stresses. We believe that our modern lentil varieties are "lazy fixer" as compared to their wild relatives, as they are bred under high fertility conditions and there is no need for them to establish relations with the rhizosphere.</p><p>To test this hypothesis, we are exploring 6 wild lentil species as well as a group of cultivated lentils to characterize their nitrogen fixing ability. The purpose is to identify specific genotypes with higher ability and to better understand potential contributions of wild plants to the domesticated lentil.</p>
2017
<p>For farmers, crops that quickly cover the ground soon after seeding ("ground-cover") generally mean fewer weeds and reduced need for in-crop herbicide applications. Plants that grow faster early in the growing season and larger as the season goes on also tend to produce higher seed yields. These traits, however, have generally been very difficult and time-consuming to quantify. Biomass, in particular, is rarely measured due to associated time, costs, and killing the entire plants early.</p><p>The goal of this project is to quantify ground-cover and plant volume using overhead imagery captured from unmanned aerial vehicles (UAV's) and handheld cameras. Image analysis is performed on 2-dimensional stitched images to determine ground-cover and on 3-dimensional point clouds to measure parameters of plant volume, which are then compared with actual above-ground biomass. These imaging can be done quickly and economically.&nbsp; No plant killing is needed so&nbsp; it is possible to collect data at multiple times throughout the growing season.</p><p>Ultimately, these imaging methods may be used to quickly and efficiently obtain plant growth and architecture information in breeding programs.</p>
2016
<p>&nbsp; &nbsp; We have many different types of lentil grown in over 50 countries around the world.&nbsp; The timing to grow the crop is different depending on where you are.&nbsp; In Canada, lentil is sown in May and harvested in August.&nbsp; Whereas in Nepal, lentil is sown in October and harvested in February the year after.&nbsp; In Mediterranean countries such as Italy, lentil is sown in October but won't be harvested until May/June.</p><p>&nbsp; &nbsp; Most lentil varieties only perform well under a specific climate and fail when they are grown in under a different climate.&nbsp; Yield is closely related to adaptation and that is why breeders tend to use only a few local varieties in their crosses.&nbsp; To allow breeders to expand their choices, we need to know how different lentils interact and adapt to different environments, i.e. changing daylength and temperature over the growing season.&nbsp; Better understanding of the genetic mechanism that affects how lentil grow and mature in a specific climatic condition will help breeders to more effectively choose the lines in their crosses.</p>
2012 to 2015
This group is involved in a wide range of biotechnology projects that accelerate the legume breeding process. Double-haploid technology has been achieved in both chickpea and field pea by the CDC group in collaboration with colleagues in France and Australia. Efforts are underway to adapt this technology to lentil. Improving efficiency and integrating these techniques into routine breeding programs to enhance genetic gain are important long-term goals.
2013 to 2015
The 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 Caco-2 mammalian cell bioassay, to determine whether iron bioavailability in field pea is heritable by evaluating recombinant inbred lines differing in phytate concentration using the Caco-2 mammalian cell bioassay, and to determine the effect of the pea low phytate trait on chicken performance and iron bioavailability in chicken.
2009 to 2012
The first objective is to improve the nitrogen contribution of pulses to the rotation by assessing the nitrogen budget of faba bean, a crop likely to have greater nitrogen fixation and growth than pea and lentil. The second is to measure the biomass and nitrogen content of a range of faba genotypes and cultivars. The third objective is to assess the nitrogen fixation ability of faba genotypes by shoot N metabolism under typical dryland prairie conditions and controlled stress conditions, and develop a specific amino-acid screening method to screen for high N fixation. We intend to use the results to screen a wider range of germplasm for improving future varieties.

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