Genetic Diversity Assessment of Acid Lime (<i>Citrus aurantifolia</i> Swingle) Landraces in Nepal, Using SSR Markers

Abstract

Acid lime (Citrus aurantifolia) is an important commercial fruits crop, cultivated in terai to high hills of Nepal. High variation of acid lime fruits are observed in existing landraces due to crossing within the other citrus species. Determination of genetic variation is important to the plant breeders for development of high yielding variety and hybrids. Therefore, an attempt has been made to study the genetic diversity of 62 acid lime landraces, collected from different altitudinal range in the eastern part of Nepal, using SSR markers. Twelve Simple Sequence Repeat (SSR) primer pairs were used to assess the genetic diversity of acid lime. The average genetic similarity level among the 62 accessions was 0.77, ranging from 0.54 to 1.0 and separated five major cluster groups. Total of 33 alleles were detected by eleven primer pairs and size of alleles ranged from 50 to 225. Average polymorphic information content (PIC) value was 0.50, whereas highest 0.75 and lowest 0.18 was observed in CAT01 and GT03 loci respectively. The results of the study clearly indicated that, SSR markers are highly polymorphic and more informative for the assessment of genetic diversity of acid lime landraces.

ISSR-Markers Assisted Genetic Diversity Assessment of Acid Lime [<em>Citrus aurantifolia </em>(Christm.) Swingle] Germplasm of Eastern Nepal

“…In our present investigation, the Terai. The result is comparable with the result obtained using SSR markers where accessions from high and mid-hills have the high average genetic similarity (73% and 81%) in comparison to Terai (69%) [39]. Our results showed that the collected accessions from different agro-ecological zones were not genetically distinct but highest diversity was observed in Terai accessions compared to in High and Mid-hills.…”

“…Accessions (LS-56, LS-57and LD-58) from Terai ecological zone are clustered together, similar to the results obtained in SSR-based phenogram by [39], indicating their genetic closeness. The intermixing of accessions that are grown in different agro-ecological domains in different clusters in the phenogram may be attributed to the genetic similarities among different accessions in various qualitative and quantitative traits.…”

“…This discrepancy in diverse gene pool could be due to higher accessibility for the movement of germplasm in Terai within the country, and also from neighboring country India. In contrast, lower level of genetic variability as was observed in Mid-hills and Highhills might be due to acid lime trees being established in natural conditions in these zones [39]. Our Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 9 May 2018 doi:10.20944/preprints201805.0144.v1…”

“…Citrus germplasm by [24,[38][39][40][41]. Although the codominant SSR marker system based genetic study was carried out prior to this study using the similar samples [39] annealing at 50C (45 s), elongation at 72C (2 m) and a final elongation at 72C (7 m), followed by a hold at 4C (for infinity) [24].…”

“…3). The first principal co-ordinate axis accounted for clustered together on phenogram generated from SSR markers [39] and RAPD markers [41].…”