Poor seed coat colour desirability in green lentil (<i>Lens culinaris</i>) costs lentil producers millions of dollars each year. The monetary value that Canadian lentil producers receive for their crop is based on the visual characteristics of the seed coat, mainly the colour. Higher value is given for samples described to have more desirable green seed coat colour. A breeding line, 1294M-23, has been noticed to consistently produce more desirable green lentil samples.<p>A cross was made between 1294M-23 and a less desirable breeding line 1048-8R with the goal of studying the heritability of green seed coat desirability measured by the Acurum® machine. The resulting progeny were taken to F7 by single seed descent. In 2005 and 2006 the recombinant inbred lines (RILs) were seeded in a randomized complete block design at three sites in the current main lentil growing region of Saskatchewan. To measure the seed coat colour of the samples, the Acurum® machine, which is a colour analyzing machine developed for grain crops, was used to consistently compare the samples. The study illustrated that the trait has large environmental effects and is quantitative with a high broad sense heritability of 0.82, using this specific cross and environments. Transgressive segregation occurred for RILs that had more desirable green seed coats and lower index scores than the desirable parent, 1294M-23. A tester that included all registered green lentil cultivars set was grown with the RILs in all environments. The seed coat colour index scores of the tester set fit into a small section of the range of index scores. They all had relatively high mean index scores, meaning less desirable, showing little genetic variation for the trait in current Canadian green lentil cultivars. <p>Chlorophyll was extracted from seed coats of some of the RILs. The amount of total chlorophyll, chlorophyll a, and chlorophyll b was compared to the Acurum® scores using regression analysis. The study found that there was significant relationship between chlorophyll a and b content and the index score, explaining 32 and 37 percent of the variation, respectively. <p>Another portion of the study was to determine if preharvest treatment of the green lentil crop has an effect on the green seed coat colour of the sample. A set of genotypes consisting of all registered green seed coat cultivars was grown at two locations in Saskatchewan in both 2005 and 2006. Prior to harvest a plot of each genotype was swathed, and a second plot was desiccated with diquat. After harvest the samples were analyzed for green seed coat colour using the Acurum® machine. In general, across most genotypes, sites, and years, swathing produced a significantly more desirable green lentil sample. The desirable green parent from the RILs, 1294M-23 produced the most desirable green lentil sample in this study. When the maturity rating was correlated to the Acurum® score a significant positive relationship was found in 2005 but not in 2006. This showed that lines with later maturity could be associated with more desirable green seed coat colour in some environments. Thus caution must be taken when selecting for more desirable phenotypes that genetic gains are being made rather than indirect selection for longer maturity.

Poor seed coat colour desirability in green lentil (<i>Lens culinaris</i>) costs lentil producers millions of dollars each year. The monetary value that Canadian lentil producers receive for their crop is based on the visual characteristics of the seed coat, mainly the colour. Higher value is given for samples described to have more desirable green seed coat colour. A breeding line, 1294M-23, has been noticed to consistently produce more desirable green lentil samples.<p>A cross was made between 1294M-23 and a less desirable breeding line 1048-8R with the goal of studying the heritability of green seed coat desirability measured by the Acurum® machine. The resulting progeny were taken to F7 by single seed descent. In 2005 and 2006 the recombinant inbred lines (RILs) were seeded in a randomized complete block design at three sites in the current main lentil growing region of Saskatchewan. To measure the seed coat colour of the samples, the Acurum® machine, which is a colour analyzing machine developed for grain crops, was used to consistently compare the samples. The study illustrated that the trait has large environmental effects and is quantitative with a high broad sense heritability of 0.82, using this specific cross and environments. Transgressive segregation occurred for RILs that had more desirable green seed coats and lower index scores than the desirable parent, 1294M-23. A tester that included all registered green lentil cultivars set was grown with the RILs in all environments. The seed coat colour index scores of the tester set fit into a small section of the range of index scores. They all had relatively high mean index scores, meaning less desirable, showing little genetic variation for the trait in current Canadian green lentil cultivars. <p>Chlorophyll was extracted from seed coats of some of the RILs. The amount of total chlorophyll, chlorophyll a, and chlorophyll b was compared to the Acurum® scores using regression analysis. The study found that there was significant relationship between chlorophyll a and b content and the index score, explaining 32 and 37 percent of the variation, respectively. <p>Another portion of the study was to determine if preharvest treatment of the green lentil crop has an effect on the green seed coat colour of the sample. A set of genotypes consisting of all registered green seed coat cultivars was grown at two locations in Saskatchewan in both 2005 and 2006. Prior to harvest a plot of each genotype was swathed, and a second plot was desiccated with diquat. After harvest the samples were analyzed for green seed coat colour using the Acurum® machine. In general, across most genotypes, sites, and years, swathing produced a significantly more desirable green lentil sample. The desirable green parent from the RILs, 1294M-23 produced the most desirable green lentil sample in this study. When the maturity rating was correlated to the Acurum® score a significant positive relationship was found in 2005 but not in 2006. This showed that lines with later maturity could be associated with more desirable green seed coat colour in some environments. Thus caution must be taken when selecting for more desirable phenotypes that genetic gains are being made rather than indirect selection for longer maturity.

ABSTRACT<p> Canada is currently the world leader in red lentil exports, a crop of significant economic importance to Western Canadian producers. It is important for the maintenance and growth of foreign markets that our growers are able to provide a consistent product. In the past few years, our exported red lentils have had variable quality, largely due variable weather conditions. A study was conducted to determine the effect of various preharvest treatments on the milling quality of our current red lentil cultivars. These cultivars, listed in order of increasing seed size, were CDC Robin, CDC Imperial CL, CDC Rosetown, CDC Blaze, CDC Impact CL, CDC Rouleau, CDC Redberry and CDC Red Rider. Replicated plots of each variety were grown in the summers of 2005 and 2006 at Floral, SK and Rouleau, SK. These were chosen with the intent of maximizing environmental differential between locations, especially in terms of soil texture and moisture availability. All locations were laid out using a randomized complete block design with four replicates. Replicated plots of each cultivar were subjected to preharvest treatments of desiccation with Diquat or swathing at early, recommended and late stages of maturity. The milling quality of the harvested lentils was determined for all treatment and cultivar combinations.<p> Before preharvest treatments were applied, each plot was assigned a maturity rating based on a 1 (immature) 9 (very mature) scale. Plants exhibiting pods with a buckskin colour and texture on the bottom third of the plant were considered to be at early maturity and assigned a rating of 3. Similarly, when pods of buckskin colour and texture were found in the middle third of the plant, a maturity rating of 6 was assigned while a value of 9 would be assessed when the entire plant had all brown, rattling pods except for a small portion of buckskin pods in the top third of the canopy.<p> Based on this 1-9 scale, a total of six different harvest treatments were carried out: swathing or chemical desiccation at early, intermediate or late stages of maturity. Swathed plots were cut using a gas-powered sickle-mower, then covered with bird mesh which was staked to the ground until harvest to prevent wind damage. Desiccated plots were sprayed with Reglone (diquat) using a CO2-pressurized backpack sprayer. They were left standing until harvest. Following mechanical harvest, seed from each plot was placed in mesh bags and forced-air-dried to approximately 13% moisture, then placed in a controlled storage chamber held at 5oC.<p> Seed samples of two complete sets of replicated treatments were cleaned, then sized by passing them over round, then slotted sieves using the forty-shakes method. The two most frequent seed diameter and thickness fractions from each plot were set aside for milling. Samples were hydrated to 12.5% moisture which is the ideal moisture content for high milling quality according to research conducted by Dr. Ning Wang at the Grain Research Laboratory in Winnipeg, MB. The samples were then milled using either a Satake or a Turkish table top pulse dehuller. Following milling, samples were passed through a Carter dockage tester (Simon-Day Ltd., Winnipeg, MB) to separate whole and split seeds from broken or damaged seeds and hull material. Each sample was assessed for: 1) milling efficiency (percent split and unsplit cotyledons recovered from the total sample); 2) football recovery (percent dehulled lentils with unsplit cotyledons); and 3) dehulling efficiency (percent of cotyledons with over 98% of the seed coat removed. Dehulling efficiency values were assessed using a DuPont AcurumTM seed scanner (DuPont Canada, Toronto, ON).<p> Under favorable harvest conditions, preharvest treatments had no effect on milling efficiency, percent football recovery or dehulling efficiency. However, plots subjected to cool, wet harvest conditions produced lentil samples of highly variable milling quality. Early desiccation significantly reduced milling efficiency to below 70%, whereas early swathing resulted in milling efficiency above 85%. CDC Robin and CDC Imperial CL had the highest milling efficiencies. Similarly, cool wet harvest conditions caused percent football recovery to drop from approximately 80% to around 50%. Early swathing was the most effective for producing footballs, with smaller-seeded varieties producing the most. Cool, wet harvest caused dehulling efficiency to drop from the 97.3 99.9% range to 91.5 98.7%. Early desiccation had the most negative effect on dehulling efficiency, whereas early swathing produced the highest values. Under these conditions, smaller-seeded varieties had the lowest dehulling efficiencies.<p> The results of this study will be valuable for developing agronomic practices specific to red lentil and for improving the quality of Canadas exported product.

ABSTRACT<p> Canada is currently the world leader in red lentil exports, a crop of significant economic importance to Western Canadian producers. It is important for the maintenance and growth of foreign markets that our growers are able to provide a consistent product. In the past few years, our exported red lentils have had variable quality, largely due variable weather conditions. A study was conducted to determine the effect of various preharvest treatments on the milling quality of our current red lentil cultivars. These cultivars, listed in order of increasing seed size, were CDC Robin, CDC Imperial CL, CDC Rosetown, CDC Blaze, CDC Impact CL, CDC Rouleau, CDC Redberry and CDC Red Rider. Replicated plots of each variety were grown in the summers of 2005 and 2006 at Floral, SK and Rouleau, SK. These were chosen with the intent of maximizing environmental differential between locations, especially in terms of soil texture and moisture availability. All locations were laid out using a randomized complete block design with four replicates. Replicated plots of each cultivar were subjected to preharvest treatments of desiccation with Diquat or swathing at early, recommended and late stages of maturity. The milling quality of the harvested lentils was determined for all treatment and cultivar combinations.<p> Before preharvest treatments were applied, each plot was assigned a maturity rating based on a 1 (immature) 9 (very mature) scale. Plants exhibiting pods with a buckskin colour and texture on the bottom third of the plant were considered to be at early maturity and assigned a rating of 3. Similarly, when pods of buckskin colour and texture were found in the middle third of the plant, a maturity rating of 6 was assigned while a value of 9 would be assessed when the entire plant had all brown, rattling pods except for a small portion of buckskin pods in the top third of the canopy.<p> Based on this 1-9 scale, a total of six different harvest treatments were carried out: swathing or chemical desiccation at early, intermediate or late stages of maturity. Swathed plots were cut using a gas-powered sickle-mower, then covered with bird mesh which was staked to the ground until harvest to prevent wind damage. Desiccated plots were sprayed with Reglone (diquat) using a CO2-pressurized backpack sprayer. They were left standing until harvest. Following mechanical harvest, seed from each plot was placed in mesh bags and forced-air-dried to approximately 13% moisture, then placed in a controlled storage chamber held at 5oC.<p> Seed samples of two complete sets of replicated treatments were cleaned, then sized by passing them over round, then slotted sieves using the forty-shakes method. The two most frequent seed diameter and thickness fractions from each plot were set aside for milling. Samples were hydrated to 12.5% moisture which is the ideal moisture content for high milling quality according to research conducted by Dr. Ning Wang at the Grain Research Laboratory in Winnipeg, MB. The samples were then milled using either a Satake or a Turkish table top pulse dehuller. Following milling, samples were passed through a Carter dockage tester (Simon-Day Ltd., Winnipeg, MB) to separate whole and split seeds from broken or damaged seeds and hull material. Each sample was assessed for: 1) milling efficiency (percent split and unsplit cotyledons recovered from the total sample); 2) football recovery (percent dehulled lentils with unsplit cotyledons); and 3) dehulling efficiency (percent of cotyledons with over 98% of the seed coat removed. Dehulling efficiency values were assessed using a DuPont AcurumTM seed scanner (DuPont Canada, Toronto, ON).<p> Under favorable harvest conditions, preharvest treatments had no effect on milling efficiency, percent football recovery or dehulling efficiency. However, plots subjected to cool, wet harvest conditions produced lentil samples of highly variable milling quality. Early desiccation significantly reduced milling efficiency to below 70%, whereas early swathing resulted in milling efficiency above 85%. CDC Robin and CDC Imperial CL had the highest milling efficiencies. Similarly, cool wet harvest conditions caused percent football recovery to drop from approximately 80% to around 50%. Early swathing was the most effective for producing footballs, with smaller-seeded varieties producing the most. Cool, wet harvest caused dehulling efficiency to drop from the 97.3 99.9% range to 91.5 98.7%. Early desiccation had the most negative effect on dehulling efficiency, whereas early swathing produced the highest values. Under these conditions, smaller-seeded varieties had the lowest dehulling efficiencies.<p> The results of this study will be valuable for developing agronomic practices specific to red lentil and for improving the quality of Canadas exported product.