GENETIC VARIABILITY CHARACTERIZATION OF SOME EX SITU CONSERVED FINGER MILLET (ELEUSINE CORACANA (L.) GAERTN. SUBSP. CORACANA) GERMPLASM ACCESSIONS IN SRI LANKAUSING QUALITATIVE MORPHOLOGICAL MARKERS

* P. N. Dasanayaka 1 and D. V. S. Kaluthanthri 1 . Department of Botany, Faculty of Applied sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History


ISSN: 2320-5407
Int. J. Adv. Res. 5 (5), 1381-1389 1382 suggest that the origin of E. coracanaprobably happened about 5000 years ago at somewhere in the region that is currently known as Uganda. It has been cultivated in India since 3000 years ago (Sirinivasacharyet al., 2007). Finger millet grain can be stored for years without storage pests, which makes it a perfect food grain commodity for famine prone areas (National Research Council 1996).
E. coracanahas a greater nutritional value. Both grain and hull of finger millet have considerable nutrient content. The grain contains carbohydrate, protein, fat, fibers, iron, calcium, minerals and essential amino acids such as leucine, tryptophan, phenylalanine and methionine.The hull contains protein, fiber, Calcium and phosphorus. Consequently, this can be considered as the major preventive agent against malnutrition. Content of each component can be changed according to the crop variety. However each and every variety has its own nutritive value.E. coracanais used as a traditional medicine for several diseases such as liver disease. Villagers make plait bracelets using leaves and clumps of this crop. Chemicals such as hydrocyanic acid are obtained from finger millet.Since finger millet grains are much harder it is less susceptible to diseases and pests. But Finger millet blast disease is one of threats for the farmers who cultivatefinger millet (Ulaganathan and Nirmalakumari, 2015).
There are several important attributes of finger millet including adaptability to adverse agro-ecological conditions with minimal inputs, tolerant to moisture stress, can be produced on marginal land where other crops cannot perform, and tolerant to acidic soil (Barbeau and Hilu, 1993).
The genetic diversity study of a crop species is essential in many aspects including effective utilization of germplasm in plant breeding programs, identification of appropriate sampling procedures for germplasm collection and conservation, obtaining some collections for efficient germplasm management and explicating the taxonomy, evolution and origin of crop species (Assefaet al., 2002;Bekele, 1985;Demissie and Bjonstrand, 1996). Therefore, important objective of any plant scientist is to identify an optimum number of plant traits which are sufficient to explain the maximum variability in the crop growth from sowing to harvest (Ulaganathan and Nirmalakumari, 2015). The present study was conducted to assess phenotypic diversity of randomly selected 42 finger millet germplasm accessions conserved at PGRC, Gannoruwa, Sri Lanka.
Major aim of this article is to reveal the few of qualitative morphological characteristics of the studied finger millet germplasm accessions. There are more studies that revealing the genetic diversity of finger millet germplasm accessions conserved in Sri Lanka using quantitative morphological markers and SSR markers (Dasanayaka

Materials and Methods:-
This study was performed on 42 germplasm accessions of finger millet conserved at the Plant Genetic Resource center (PGRC), Gannoruwa, Sri Lanka (Table 01). These 42 germplasm accessions comprised of 27 Sri Lankan accessions, 11 Indian accessions, 2 Zimbabian accessions and 2 recommended varieties of Sri Lanka.
Seeds of each accession were sown in small plastic pots filled with normal soil, and keep the spacing between the seeds. Pots were irrigated soon after sowing and placed in a plant house. Two weeks old seedlings were transplanted separately in the large plastic pots filled with mixture of soil, sand and compost (1:1:1) as each pot contained 4 plants. Data were recorded on twelve qualitative parameters. Qualitative traits taken into consideration were Pigmentation, Growth habit, Ear shape, Ear size, Finger branching, Discontinuity of spikelet, Lodging susceptibility, Spikelet shattering, Grains covering by glumes, Grain colour, Grain shape and Grain surface. Characters were scored following International Plant Genetic Resource Institute (IPGRI) descriptors developed for finger millet.
Data Analysis:-Frequency distribution of ten polymorphic qualitative traits and its graphical representation were obtained using software IBM SPSS Statistics version 21 and Microsoft office excel 2007. plant showed any kind of pigmentation or finger branching. The frequency distribution of ten polymorphic qualitative traits is given in Table 02 and its graphical representation is shown in Figure 01. Regarding Spikelet shattering at maturity, majority of plants (95.0%) were not found to possess ears which shattered their spikelet at maturity.
Three types of glumes were observed in this study. Most of grains (71.6%) were completely covered by glumes (Enclosed) and 17.4% of grains was partially covered by glumes (Intermediate). Remaining 11.0% of grains was not covered by glumes.  , three morphological states of grains covered by glumes (exposed, intermediate and enclosed), four morphological states of grain color (white , light brown, copper brown and dark brown), two morphological states of grain shape (round and reniform) and two morphological states for grain surface (smooth and wrinkled)were observed in studied finger millet germplasm accessions. Furthermore, discontinuity of spikelet on finger and spikelet shattering at maturity were not observed in majority of germplasm accessions used in this study.

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According to the plant colour, finger millet germplasm accessions can be classified into two groups as green colour plants and pigmented plants. There were no pigmented plants with respect to any of studied accessions. Therefore, the trait, pigmentation can be considered as a monomorphic character in this study. Similarly, the character, finger branching can be considered as a monomorphic character reason being not observed in any of studied accessions.
Decumbent, erect and prostrate are the three types of growth habit that can be found in finger millet. In this study, erect type was predominant with frequency of 71.4% followed by prostrate type with frequency of 24.0% where as prostrate type was found in only few individuals from several accessions. However as Bezaweletawet al. (2007) reported the variation in growth habit showed that the decumbent type was more predominant in all regions followed by prostrate type with overall frequency of 25% whereas erect type was found to concentrate in one region with a frequency of 34%. Type of growth habit of a plant involves in its capacity to suppress weeds at early growth stage and its capacity to withstand against the moisture stress. Apparently, if the architecture of a plant can reduce the evapo-transpiration by covering the soil at early stage such architecture could enable the plant to perform better. According to Bezaweletawet al.(2007), prostrate type and decumbent typemight be highly preferred by most farmers in different regions which could be due to their capacity to suppress weeds at early growth stage and ability to withstand moisture stress.
According to De Wet et al. (1984), inflorescence morphology was associated with grain yield and is used by the farmers to distinguish complexes of cultivars. In this study semi-compact type of ear shape was predominant with frequency of 68.0% whereas droopy ear shape was not found in any plant.
In In this study 92.0% of plants did not show discontinuity of spikelet on finger.
Lodging can be defined as the permanent displacement of a plant from its vertical position. Lodging of finger millet plants was recorded by looking at the angle of displacement of the stem from the vertical position where 0° is no displacement. In this study, no lodging was predominant with frequency of 61.8% followed by low lodging with frequency of 18.6% whereas intermediate and high lodging plants were found with equal frequency of 9.8%. In finger millet, grain yield can be reduced mainly due to moisture scarcity and lodging susceptibility of the plants.
And also lodging can be resulted in shriveled and poor quality seed that sprouts on the panicle before harvest. Plant height and Culm thickness have major effect on the lodging susceptibility of a plant.
Spikelet shattering at maturity was absent in 95.0% of plants in this study. One of the key changes often regarded as the characteristic of domesticated grain crops was a shift from natural seed dispersal through shattering mechanisms to obligate dispersal by people (Zohary, 1969;Harlan et al., 1973;Davies, 1990, 1999). Shattering occurs by the abscission at the abscission scars, such as the rachilla to spikelet base attachment. But as a result of the loss of abscission at the abscission scars, a plant retains seeds instead of shedding them when they are mature and they are then usually separated by the addition of human labour (threshing and winnowing). This increases the efficiency of harvest and thus yields.
In this study, Majority of plants (71.6%) composed of enclosed grains covering by glumes. In other words majority of grains had tightly bound seed coats with their edible part. However this character state is kind of a challenge to threshing and milling processes (Tsehay and Kebebew, 2002).
Four different grain colours including Light brown (35.0 %), Dark brown (30.0%), Copper brown (27.0%) and White (8.0%) were observed in this study. However, purple brown coloured grains were not found in this study. Grain colour can be considered as one of the most important traits reason being its involvement in the determination of the quality of the cultivars. As described by Tsehaye and Kebebw (2002), grain colourhas an economic value because it is used in variety identification and commercial classification of different varieties of crops. White and reddish coloured grains have considerably high economic value compared to that of dark coloured grains. But farmers prefer to grow dark coloured grains because of its high yield and hardiness with respect to climatic hazards such as poor soil fertility. (Kefyalew and Ensermu, 1989). An apparent association between grain colour and human consumption of finger millet can be observed with in Ethiopia as reported by Zemede (1988).

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In this study, round shaped grains and smooth surface grains were predominant with frequencies of 97.0% and 95.0% respectively. As reported by Bezaweletawet al. (2007), though their adaptive significance is not known, grains with round shape and smooth surface are preferred by consumers in Ethiopia. In the case of finger millet consumption, threshing and milling processes should be performed beforehand. In here, especially in milling, round shaped and smooth surfaced grains might be more advantageous.

Conclusion:-
The genetic diversity study of a crop species is essential in many aspects including effective utilization of germplasm in plant breeding programs, identification of appropriate sampling procedures for germplasm collection and conservation, obtaining some collections for efficient germplasm management and explicating the taxonomy, evolution and origin of crop species.In this process, qualitative characters are useful in precise characterization of germplasm. The study of 12 qualitative characters revealed that the considerable morphological variation exist among the studied accessions especially for characters such as growth habit, ear shape, ear size, lodging sisceptibility, grain covering by glume and grain colour. Findings of this study provide a clue for germplasm collection and conservations.