Genetic variation for tolerance to post-emergence herbicide,imazethapyr in lentil (Lens culinaris Medik.)

Weeds pose a serious constraint to lentil production. Identification and deployment of post-emergence herbicide tolerance in improved varieties can help reduce the production cost and increase the productivity and area under lentil cultivation. Imazethapyr, a post-emergence herbicide was tested on 180 lentil genotypes for two consecutive years. Significant variation among the genotypes was observed for tolerance to imazethapyr. On a 1–5 scale, 12 genotypes were found tolerant, 46 moderately tolerant, 112 sensitive and 10 highly sensitive during the first season, and 11 genotypes were found tolerant, 51 moderately tolerant, 110 sensitive and 8 highly sensitive during the second season. Based on the first year’s result, 30 genotypes, representing tolerant, moderately tolerant, sensitive and highly sensitive reactions, were evaluated to determine the effect of herbicide on morpho-physiological and yield traits. The adverse effect of imazethapyr was significant on growth and yield attributes of lentils. Five genotypes namely LL699, LL1397, IPL406, EC78452 and LL1203 demonstrated tolerance to imazethapyr with limited phytotoxic effect on various morpho-physiological traits. These genotypes showed less reduction (<19%) for seed yield in imazethapyr treated plots as compared to control. These genotypes offer scope for developing post-emergence herbicide tolerant cultivars in lentil.     

Characterization of Italian lentil (Lens culinaris Medik.) germplasm by agronomic traits, biochemical and molecular markers

Genetic relationships, agronomic, nutritional and technological traits of ten Italian landraces, two improved lines and two cultivars of lentil (Lens culinaris Medik.) were investigated using a multi-disciplinary approach. Seed storage proteins, used as biochemical markers, were able to detect polymorphisms with variability mainly related to the polypeptide abundance. Microsatellite (SSR) molecular markers provided very useful information on genetic variation and relationships among landraces, with polymorphic fragments able to discriminate all the accessions. Lentil landraces were grouped in different clusters and sub-clusters principally on the basis of their geographical origin. The highest levels of genetic diversity were observed for lentils from ‘Castelluccio di Norcia’, ‘Colliano’ and ‘Villalba’. Field trials, performed in two locations of Southern Italy, revealed a high influence of location on yield. Comparing performances at both tested locations, the best landraces were ‘Linosa’ and ‘Valle di Nevola’ suggesting that these have the highest adaptability. Technological and nutritional data together with the agronomic ones evidenced that ‘Linosa’ lentil is the best landrace, however also ‘San Gerardo’ deserves some attention.     

Selection of Rhizobium isolates able to improve productivity of lentil (Lens culinaris Medik)

Abstract

Nitrogen-fixing efficiency is influenced by genetic combination of rhizobia strain/legume genotype. In this research, 48 rhizobia isolates from lentil (Lens culinaris Medik) were characterized for DNA polymorphism and assayed for their ability to improve, in open field, grain yield of lentil. By DNA polymorphism analysis, only four haplotypes were observed for Rhizobium isolates from lentil seeds, whereas a higher genetic variability was observed for Rhizobium isolates obtained from root-tubercles. The performance of the 11 rhizobia haplotypes was analysed in the field after inoculation on two Italian lentil ecotypes. Two isolates of rhizobia induced a significant improvement of grain yield (plus from 37% to 40% with respect to non-inoculated plants) on the Colfiorito ecotype, whereas no significant improvement of yield was obtained on Colliano.     

Morphological features of an open flower mutant plant and characterization of their progenies in lentil (Lens culinaris Medik.)

The lentil (Lens culinaris Medik.) is a self-pollinated seed legume with cleistogamous flowers. A spontaneous open flower semi leaf-less mutant, was observed from segregating generation (F₄) of a cross IPL 313 × RKL 1001 in which reproductive organs were not enclosed by the keel petals and thus remained exposed. Leaves on this mutant plant was very less and random with 1–3 pairs of leaf lets whereas in normal plant leaves are present at every reproductive node with 5–7 pairs of leaf lets. A very large number of open flowers (>90 %) remained sterile in mutant plant and their progenies, though its pollen fertility was as high as the standard cultivars. The progenies of the mutant open flower plant were segregates in three morphological different plant types as (1) open flower leaf-less plants, (2) open flower semi leaf-less plants and (3) normal plants having cleistogamous (closed) flowers and normal bearing leaves. The open flower leafless plant were low yielder whereas open flower semi leafless progenies have good yield potential and are important source of rare novel mutant alleles for important economic traits like multiple peduncles per reproductive node, more number of flowers/pods per peduncle and long reproductive phase. The open flower trait offers opportunity for exploring hybrid technology in the lentil and mutant alleles can play a crucial role in understanding the genetics of the target trait and for improvement of lentils.     

The evolution of lentil (Lens culinaris Medik.) cultivation in Italy and its effects on the survival of autochthonous populations

At the beginning of the 20th Century Italy was one of the most important producers of lentil in the Mediterranean basin. Presently, this pulse is mainly cultivated in marginal areas of Central and Southern Italy and in some small islands. As a result of the reduced attention devoted to lentil, several autochthonous populations have disappeared together with the traditions related to their cultivation. Moreover, how long the cultivation of those still grown today will continue is unpredictable. Governmental and local associations have a time window for anticipating a possible epoch when to grow these landraces will be no longer profitable. In the last decades the Germplasm Institute of the National Research Council (Bari, Italy) and the Institut für Pflanzengenetik und Kulturpflanzenforschung (Gatersleben, Germany) have collected 63 lentil populations in Italy, presently stored ex situ. The evaluation of this collection has shown the existence of an appreciable morphological, agronomic and genetic diversity that could foster future breeding programmes. It is concluded that there is an urgent need to promote the survival of lentil populations in situ, since this will further support the adaptation and evolution of autochthonous genotypes in their original environments.     

Simple and rapid method for the differentiation of Lens culinaris Medik. from false lentil species

The practice of using both common vetch (Vicia sativa L.) and single-flower vetch (Vicia articulata Hornem.) seeds as food or feed is encouraged by the very high resemblance of their seeds with those of small-seeded lentil cultivars. Among the Vicieae, antinutritional and toxic factors are particularly important, because many species, containing high levels of these compounds, are not safe. A simple and fast capillary electrophoresis (CE) method was proposed for the differentiation of lentil cultivars from false lentil species (i.e., single-flour vetch and common vetch). Proteins were extracted from defatted milled seeds with an alcoholic/saline solution. Extracts were separated in an uncoated fused-silica capillary with iminodiacetic acid (IDA) isolectric buffer containing 0.05% hydroxypropylmethylcellulose (HPMC) and 20% acetonitrile. The presented method is useful also for the detection of contamination of whole or split seeds of lentil by vetch species. With respect to alternative techniques, such as DNA-based markers or thin-layer chromatography (TLC), CE has the advantages of being less expensive, faster, and fully automated.     

Evaluation of vermicompost fertilizer application on growth,nutrient uptake and photosynthetic pigments of lentil (Lens culinaris Medik.) under moisture deficiency conditions

Vermicompost can play an effective role in plant growth and also in reducing harmful effects of various environmental stresses on plants due to its porous structure, high-water storage, having hormone-like substances and also high levels of macro and micro nutrients. Application of vermicompost in soil, especially at the levels of 15 and 25 Wt% significantly increased all studied traits under non-stress conditions. Under temperate and severe stress conditions, vermicompost at 25 Wt% treatment resulted in a significant increase in plant height (+10% +21%), number of pod (+44% +65%), root dry weight (+63% +66%), shoot dry weight (+50% +89%), leaf area (+6% +7%), root area (+65% +35%). The leaf calcium (Ca) (+62% +67%), leaf potassium (K) (+39% +45%) and root Ca (+33% +34%) under temperate and severe stress, increased using of 25% vermicompost. In conclusion, we suggested that application of vermicompost had a positive effect on lentil under moisture deficit stress.     

Quantitave evaluation of Ethiopian landraces of lentil (Lens culinaris)

Summary One hundred and fifty-six landrace populations of lentil (Lens culinaris Medikus) collected from 10 provinces in Ethiopia were evaluated for a set of six quantitative traits at three sites contrasting in altitude. Consistent regional differences among landraces were found for time to flower and maturity, 100-seed weight, number of seeds/pod and plant height. The regional differences were clarified by a discriminant analysis based on 100-seed weight, time to flower and plant height. The lentil of the West Highlands was early and short, that of the North Highlands was large-seeded, whereas lentils from the Central Highlands were the least distinctive group. Selection for seed size was the result of local human preferences. Humans were probably also responsible for the lack of adaptive value of plant phenology in relation to altitude. Selection for seed yield at the low and middle elevation sites gave a positive response to selection at both sites. However, selection for yield at the highland site did not give a positive response elsewhere, indicating that adaptation to highland conditions differed from that at lower elevations.     

Effect of soil tillage and weed control methods on weed biomass and yield of lentil (Lens culinaris Medic.)

Abstract

The study was carried out in dryfarming areas in Ankara, Turkey, over 2 years (2001 – 2002 and 2002 – 2003). The objective was to determine different soil tillage and weed control methods on weed biomass and yield components, yield of lentil (Lens culinaris). This study compared the effects of two tillage systems (shallow minimum tillage and traditional tillage) and three weed control methods (weedy check, hand weeding and herbicide) on weed biomass, growth characteristics, seed yield and some yield components of lentil. Significant differences were found among weed control methods for weed biomass and yield parameters of lentil. Tillage systems had no significant effect on weed biomass or yield of lentil. The highest yield and lowest weed biomass was found in the hand-weeded treatment compared to the other weed control methods. Results of this research indicate that weeds are a main constraint for lentil growing under dryland conditions. Grain yield of lentil was reduced more than 60% due to uncontrolled weeds.     

High potential for selenium biofortification of lentils ( Lens culinaris L.)

Beneficial forms of selenium (Se) and their impact on human health are a global topic of interest in public health. We are studying the genetic potential for Se biofortification of pulse crops to improve human nutrition. Lentils ( Lens culinaris L.) are an important protein and carbohydrate food and are a valuable source of essential dietary components and trace elements. We analyzed the total Se concentration of 19 lentil genotypes grown at eight locations for two years in Saskatchewan, Canada. We observed significant genotypic and environmental variation in total Se concentration in lentils and that total Se concentration in lentils ranged between 425 and 673 microg kg(-1), providing 77-122% of the recommended daily intake in 100 g of dry lentils. Over 70% of the Se was present as selenomethionine (SeMet) with a smaller fraction (<20%) as inorganic Se and very small amounts as selenocysteine (SeCys). We found that soils from the locations where the lentils were grown were rich in Se (37-301 microg kg(-1)) and that lentils grown in Saskatchewan have the potential to provide an excellent natural source of this essential element. Our analyses gave us a preliminary understanding of the genetic basis of Se uptake in lentil and indicated that any potential strategy for micronutrient biofortification in lentil will require choice of field locations that minimize the spatial variability of soil Se content.     

Antioxidant activity and phenolic compositions of lentil (Lens culinaris var. Morton) extract and its fractions

Phenolic compounds were extracted from Morton lentils using acidified aqueous acetone. The crude Morton extract (CME) was applied onto a macroresin column and desorbed by aqueous methanol to obtain a semipurified Morton extract (SPME). The SPME was further fractionated over a Sephadex LH-20 column into five main fractions (I-V). The phytochemical contents such as total phenolic content (TPC), total flavonoid content (TFC), and condensed tannin content (CTC) of the CME, SPME, and its fractions were examined by colorimetric methods. Antioxidant activity of extracts and fractions were screened by DPPH scavenging activity, Trolox equivalent antioxidant capacity (TEAC), ferric reduced antioxidant power (FRAP), and oxygen radical absorbing capacity (ORAC) methods. In addition, the compositions of active fractions were determined by HPLC-DAD and HPLC-MS methods. Results showed that the fraction enriched in condensed tannins (fraction V) exhibited significantly higher values of TPC, CTC, and antioxidant activity as compared to the crude extract, SPME, and low molecular weight fractions (I-IV). Eighteen compounds existed in those fractions, and 17 were tentatively identified by UV and MS spectra. HPLC-MS analysis revealed fraction II contained mainly kaempferol glycoside, fractions III and IV mainly contained flavonoid glycosides, and fraction V was composed of condensed tannins. The results suggested that the extract of Morton lentils is a promising source of antioxidant phenolics and may be used as a dietary supplement for health promotion.     

Screening of postharvest agricultural wastes as alternative sources of peroxidases: characterization and kinetics of a novel peroxidase from lentil ( Lens culinaris L.) stubble

Aqueous crude extracts of a series of plant wastes (agricultural, wild plants, residues from sports activities (grass), ornamental residues (gardens)) from 17 different plant species representative of the typical biodiversity of the Iberian peninsula were investigated as new sources of peroxidases (EC 1.11.1.7). Of these, lentil (Lens culinaris L.) stubble crude extract was seen to provide one of the highest specific peroxidase activities, catalyzing the oxidation of guaiacol in the presence of hydrogen peroxide to tetraguaiacol, and was used for further studies. For the optimum extraction conditions found, the peroxidase activity in this crude extract (110 U mL(-1)) did not vary for at least 15 months when stored at 4 °C (k(inact) = 0.146 year(-1), t(1/2 inact) = 4.75 year), whereas, for comparative purposes, the peroxidase activity (60 U mL(-1)) of horseradish (Armoracia rusticana L.) root crude extract, obtained and stored under the same conditions, showed much faster inactivation kinetics (k(inact) = 2.2 × 10(-3) day(-1), t(1/2 inact) = 315 days). Using guaiacol as an H donor and a universal buffer (see above), all crude extract samples exhibited the highest peroxidase activity in the pH range between 4 and 7. Once semipurified by passing the crude extract through hydrophobic chromatography on phenyl-Sepharose CL-4B, the novel peroxidase (LSP) was characterized as having a purity number (RZ) of 2.5 and three SDS-PAGE electrophoretic bands corresponding to molecular masses of 52, 35, and 18 kDa. The steady-state kinetic study carried out on the H(2)O(2)-mediated oxidation of guaiacol by the catalytic action of this partially purified peroxidase pointed to apparent Michaelian kinetic behavior (K(m)(appH(2)O(2)) = 1.87 mM; V(max)(appH(2)O(2)) = 6.4 mM min(-1); K(m)(app guaicol) = 32 mM; V(max)(app guaicol) = 9.1 mM min(-1)), compatible with the two-substrate ping-pong mechanism generally accepted for peroxidases. Finally, after the effectiveness of the crude extracts of LSP in oxidizing and removing from solution a series of last-generation dyes present in effluents from textile industries (1) had been checked, a steady-state kinetic study of the H(2)O(2)-mediated oxidation and decolorization of Green Domalan BL by the catalytic action of the lentil stubble extract was carried out, with the observation of the same apparent Michaelian kinetic behavior (K(m)(appGD) = 471 μM; V(max)(appGD)= 23 μM min(-1)). Further studies are currently under way to address the application of this LSP crude extract for the clinical and biochemical analysis of biomarkers.     

Proanthocyanidin composition in the seed coat of lentils (Lens culinaris L.)

Lentils (Lens culinaris L.) are a popular food in many countries. However, little is known about their phenolic composition. Because polyphenols in lentils are located essentially in their seed coat, the objective of this work was to study the composition of proanthocyanidins, the major group of polyphenols, in this part of the tissue. The use of C(18) Sep-Pak cartridges permitted the fractionation of lentil seed coat extract into monomer, oligomer, and polymer proanthocyanidin fractions. Subsequent thiolysis of oligomer and polymer fractions followed by HPLC analysis allowed the mean degree of polymerization (mDP) and the structural composition of proanthocyanidins to be determined. A fractionation of lentil seed coat extracts on a polyamide column followed by HPLC and HPLC-DAD-MS analyses was used to identify the individual proanthocyanidins. The results showed that the major monomeric flavan-3-ol was (+) catechin-3-glucose, with lesser amounts of (+)-catechin and (-)-epicatechin. In the oligomer fraction, various dimer, trimer, and tetramer proanthocyanidins constituted of catechin, gallocatechin, and catechin gallate units were identified, and several procyanidins and prodelphinidins from pentamers to nonamers constitute the polymer fraction. The most abundant proanthocyanidins in the seed coat of lentils are the polymers (65-75%), with a mDP of 7-9, followed by the oligomers (20-30%), with a mDP of 4-5.     

Carbohydrate Concentration in Lentils (Lens culinaris Medikus.): Genotypic and Environmental Effects

Lentils contain a range of prebiotic carbohydrates; however, genotypic and environmental implications of these components have not been well understood. The objective of this study was to determine the genetic and environmental variation of carbohydrate concentrations in three commonly grown lentil cultivars in South Dakota, USA at two locations over two growing seasons. Significant genetic and environmental variation was found for most of the constituents evaluated. Raffinose-family oligosaccharides (RFO) ranged from 3161 mg 100g^?1 at Bison and 3670 mg 100g^?1 at Wall and from 3217 mg 100g^?1 to 3650 mg 100g^?1 between cultivars. Moreover, RFO content was strongly correlated to a simple plant stress index (SI) in which higher estimated plant stress (e.g., low precipitation) produced higher levels of RFO. These results demonstrate important differences in prebiotic concentrations, which can be used for future lentil breeding efforts when matching cultivars to diverse growing climates with highly variable growing season precipitation.     

Nutritional utilization by the rat of diets based on lentil (Lens culinaris) seed meal or its fractions

The nutritional effects in the rat of raw lentil meal or its fractions have been evaluated in three feeding trials. Growth, gain/feed ratio, apparent N digestibility, and N retention were significantly (p < 0.05) reduced by the inclusion of whole lentil meal, dehulled lentil meal, or ethanol-extracted lentil meal as the sole source of protein in the diet. Pure lentil lectin and lectin-depleted albumin proteins had no significant negative effect on nutritional performance. In contrast, growth, gain/feed ratio, protein conversion efficiency, N digestibility, and N retention were significantly (p < 0.05) reduced by diets containing lentil globulins or lentil hulls. The poor nutritional quality of raw lentil meal for rats is therefore likely to be primarily due to the combined effects of these two components.     

Production potential and competitive indices of Indian mustard (Brassica juncea L.) based intercropping with wheat (Triticum aestivum L.) and lentil (Lens culinaris L.) under different row ratios of eastern Uttar Pradesh

A field experiment was conducted during the (rabi) seasons of 2009–2010 and 2010–2011 at the research farm, Department of Agronomy, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, to find out the suitable row ratio of Indian mustard (Brassica juncea L.) intercropping with wheat (1:9, 2:9, 1:6, 2:6) and lentil (1:4, 1:5, 2:4, 2:5) row ratios, respectively. The highest yield attributes of mustard were recorded with mustard + lentil (2:5), which was significantly superior to mustard + wheat (1:9) and mustard + lentil (1:5). Maximum seed yield and stover yield of mustard was recorded with mustard + lentil (2:4), which was being significant over other row ratios of mustard + wheat (1:6, 1:9, 2:9) but was at par with mustard + lentil (1:5) and mustard + wheat (2:6) row ratios. Mustard equivalent yield (3128 kg ha^?1) recorded under intercropping of mustard with wheat in 1:9 row ratio was significantly higher than sole cropping of mustard, wheat, and lentil, and other remaining intercropping systems. Intercropping of mustard with wheat in 1:9 row ratio showed the highest land equivalent ratio (1.51), aggressivity index (+0.15), net return (60,468 Rs ha^?1), and benefit:cost ratio (4.3) among all other intercropping treatments.     

Sources of resistance to ascochyta blight in wild species of lentil (<Emphasis Type="Italic">Lens culinaris</Emphasis> Medik.)

Cultivated lentil (Lens culinaris Medik. subsp. culinaris) has a relatively narrow genetic base and many commercial cultivars are susceptible to ascochyta blight caused by Ascochyta lentis Vassilievsky. A total of 375 accessions of six wild species of lentil received from ICARDA and 18 cultivated genotypes were screened for resistance to A. lentis under both field and greenhouse conditions in Saskatoon, Canada. A mixture of three monoconidial isolates of A. lentis was used as an inoculum and the level of infection rated using the Horsfall-Barratt scale (0–11). Accessions with resistance to A. lentis were observed in all wild species except for L. culinaris subsp. tomentosa (Ladiz.) Ferguson et al. showing no resistant accessions. Several consistently resistant accessions were found among entries of L. ervoides (Brign.) Grande and L. nigricans, (M. Bieb.) Godr., both of which belong to the secondary gene pool and a few in L. culinaris subsp. orientalis (Boiss.) Ponert and L. culinaris subsp. odemensis (Ladiz.) Ferguson et al. belonging to the primary gene pool. Some accessions of L. ervoides exhibited lower disease ratings and AUDPC values than the resistant control cv. ‘Indianhead.’ Thirteen accessions, previously reported as resistant to Syrian isolates of A. lentis were also resistant to the Canadian isolates; some also had resistance to anthracnose. The highest frequency of resistance was found in accessions of L. ervoides which originated from Syria and Turkey. These wild accessions represent a useful and untapped source for improving disease resistance in lentil.     

Chemical form of selenium in naturally selenium-rich lentils (Lens culinaris L.) from Saskatchewan

Lentils (Lens culinaris L.) are a source of many essential dietary components and trace elements for human health. In this study we show that lentils grown in the Canadian prairies are additionally enriched in selenium, an essential micronutrient needed for general well-being, including a healthy immune system and protection against cancer. Selenium K near-edge X-ray absorption spectroscopy (XAS) has been used to examine the selenium biochemistry of two lentil cultivars grown in various locations in Saskatchewan, Canada. We observe significant variations in total selenium concentration with geographic location and cultivar; however, almost all the selenium (86-95%) in these field-grown lentils is present as organic selenium modeled as selenomethionine with a small component (5-14%) as selenate. As the toxicities of certain forms of arsenic and selenium are antagonistic, selenium-rich lentils may have a pivotal role to play in alleviating the chronic arsenic poisoning in Bangladesh.     

Yield enhancement and phosphorus economy in lentil (Lens culinaris Medikus) with integrated use of phosphorus,Rhizobium and plant growth promoting rhizobacteria

The study evaluated the effects of phosphorus (0, 20, 30, and 40 kg P₂O₅ ha^?1) and biofertilizers [Rhizobium (Rhizobium leguminosarum bv viciae), plant growth promoting rhizobacteria (PGPR) (Pseudomonas fluorescens), Rhizobium + PGPR, and uninoculated control] in lentil. Application of 40 kg P₂O₅ ha^?1 resulted in the highest number of nodules, nodule dry weight, leghemoglobin content in nodules, chlorophyll content, yield attributes, and grain yield. Coinoculated treatment performed better than uninoculated control, and individual inoculations of Rhizobium and PGPR in terms of all above mentioned parameters. Application of 20 kg P₂O₅ ha^?1 + Rhizobium inoculation gave statistically similar and 20 kg P₂O₅ ha^?1 + Rhizobium + PGPR inoculation gave significantly higher grain yield than that by 40 kg P₂O₅ ha^?1 alone. The use of Rhizobium alone and Rhizobium + PGPR consortium can save not only 20 kg P₂O₅ ha^?1 but also increase the grain yield of lentil.