Evaluation of Genetic Diversity in Lemons and Some of Their Relatives Based on SRAP and SSR Markers

Abstract

Genetic diversity was evaluated by sequencerelated amplified polymorphism (SRAP) and simple sequence repeat (SSR) markers among 45 lemons (Citrus limon (L.) Burm. f.), five citrons (Citrus medica L.), four rough lemons (Citrus jambhiri Lush), and two Citrus volkameriana accessions. Twenty-one SRAP primer combinations produced a total of 141 (77%) polymorphic fragments with an average of 6.7 fragments per primer combinations whereas 13 SSR primers produced a total of 26 (76%) polymorphic fragments with an average of 2.0 per primer. The unweighted pair-group method arithmetic average analysis as assessed with combined SRAP and SSR data demonstrated that the accessions had a similarity range from 0.65 to 1.00. Rough lemons and C. volkameriana accessions were relatively closely related. In lemon group, accessions from hybrid origin were distant from the others. We also applied principal components analysis (PCA) for a better presentation of relation among the accessions studies. Using PCA, 88.7% of the total variation in the original dimensions could be represented by just the two dimensions defined by the first two PCs. Although nearly all accessions could be distinguished, there was a low level of genetic diversity detected among lemon cultivars.

Genetic Diversity in Citrus

“…At the same way, C. volkameriana was clustered with rough lemon as in the RAPD (Luro et al, 1992) and SCAR (Nicolosi et al, 2000) based studies. It is reported there was low level of polymorphism among most of lemons derived via clonal selection whereas higher genetic diversity was found in lemons which had hybrid origin (Uzun et al, 2011b). Genetic similarity of 45 lemons included both mutation and hybrid origin was notified between 0.80-1.00 (Fig.…”

“…Similarly, Gulsen and Roose (2001), reported that similarity level of citron and lemon-rough lemon group was 0.65 based on their ISSR data. On the other hand, according to Uzun et al (2011b), genetic similarity among lemons and rough lemon-C. volkameriana group was 0.80. Rough lemons and C. volkameriana were closely related.…”

“…On the other hand, 'Song Panache' lemon have similar-shaped fruit as 'Ponderosa'. Another hybrid origin lemon 'Meyer' also separated from other lemons based on SRAP and SSR data (Uzun et al, 2011b). This cultivar was classified as lemon-resembling fruit by Hodgson (1967).…”

“…Interdonato' lemons was clearly separated from others and genetic similarity among 'Interdonato' lemons was very high caused by their mutation origin (Uzun et al, 2011b). This cultivar was reported as a hybrid between lemon and citron (Hodgson 1967;Gulsen and Roose 2000).…”

“…They evalutaed 56 accessions were evaluated (Uzun et al, 2011b). Similarity level of citrons to other accessions were ~0.70.…”