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Lentil's morphological, biochemical characters identified

RECORDER REPORT

FAISALABAD: Pathology expert Shahbaz Talib Sahi of the Agriculture University has identified morphological and biochemical characters of lentil (Masoor), which play an important role in the determining of the genetic resistance against Ascochyta blight disease.

Talking to the newsmen here on Saturday Sahi said that the low yield of lentil in Pakistan are due to continuous cultivation with low yield potential excess vegetative growth, narrow adaptability, low stability of yield, and susceptibility to stress conditions as well as inadequate nitrogen nutrition.

One of the most important stresses is damage by diseases, out of which blight is caused by Ascochyta lentils causes losses in yield up to 40 percent, especially under cool and moist conditions.

He said this disease can be managed through a number of means, the cheapest and most practicable being the use of resistant varieties. Although resistance to lentil blight is not scarce in the existing lentil cultivars yet the morphological and biochemical basis of resistance is not clearly known, he added.

Sahi pointed out that lentil contains 28.6 percent total carbohydrates (44.3 percent Starch, 36.1 percent amylose), 4.6 percent crude fibre, 3.1 percent ash and 420 calories/100 gram, gross energy. Moreover, lentils are lower in anti-nutritional factors such as haemagglutinins, oligosaccharides and favogens as compared with other legumes. Although they contain tannins in the seed coat, but not in the cotyledona. The high level of protein together with a lower level of anti-nutritional factors and a shorter cooking time than most of other pulses, make lentil very suitable for human consumption.

He said that lentil is grown over an area of 3.287 million hectares in the world, 36.51 percent being occupied by India, 5.27 percent by Bangladesh, and 2.10 percent by Pakistan, the total share in world production by these countries being 31.77 percent, 5.90 percent and 1.21 percent.

He observed that the susceptible plants had more nitrogen, phosphorus, magnesium, copper and zinc as compared with resistant plant, while the resistant plant had more potassium, sodium and calcium. Upon inoculation with the pathogen, the nitrogen, potassium, sodium, calcium, zinc copper and iron contents, increased invariably in both the groups of lentil lines.

Sahi extracted phenolic compounds from the healthy as well as diseased plants of both resistant and susceptible lentil plants by using methyl alcohol, n-hexane and ethyl acetate. The amount of total phenols was higher in case of susceptible group prior to inoculatin with the pathogen, compared with the resistant group, he added.

He also explained that upon inoculation total phenols increased significantly in both groups, the increase being more pronounced in case of resistance, that is why there is more accumulation of phenolic compounds in the resistant plants than the susceptible ones upon artificial inoculation with the pathogen.

Sahi also pointed out that the resistant lentil lines contained higher amounts of arginine, aspartic acid, valine, loucine, tyrosine and phenylalanine than the susceptible ones prior to inoculation with the pathogen, whereas higher amounts of threonine, serine, glutamic acid, proline, glycine, alanine, methionine and isoloucine were detected in the susceptible group as compared with the resistant one.

These finding will provide strong basis for the evolution of disease resistant lentil varieties, he concluded.