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Sequence-related amplified polymorphism (

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Turkey is an important citrus-producing country. However, new cultivars are needed to sustain citrus production and ensure its competitiveness against other crops. There are currently several citrus breeding programs that aim to help overcome the lack of local commercial varieties and to contribute to Turkey’s competitive capacity in the citrus market. In this study, we report the utilization of molecular markers in one such breeding program. Simple sequence repeat (SSR) markers were employed to eliminate nucellar individuals from a hybrid population produced by crossing. The crosses included ‘Fremont’ and ‘Robinson’ mandarins as the female parents and ‘Midknight Valencia’, ‘Rhode Red Valencia’, and ‘Valencia Late’ oranges and ‘Rio Red’ grapefruit cultivars as the male parents. Seedlings with the same banding patterns as the female parent were identified as nucellar seedlings by 11 SSR primers. Primers AG14 and TAA03 were found to be more effective at identifying zygotic individuals than other primers. ‘Fremont’ and ‘Robinson’ mandarins produced 36.91% and 31.09% of nucellar seedlings, respectively. As a pollen parent, ‘Rio Red’ grapefruit had a higher ratio of zygotic seedlings compared to ‘Midknight Valencia’, and can be recommended in breeding programs. Comparative analysis of different citrus fruits in the breeding programs allowed us to design an efficient hybridization scheme for this study.

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Grapefruit is the fourth economically most important citrus fruit in the world. In this research Inter-Simple Sequence Repeat (ISSR) markers were used to distinguish twenty-nine grapefruit (Citrus paradisi Macf.), five pummelo (Citrus maxima (Burm.) Merr.) and one Citrus hassaku Hort. Ex Tanaka accessions. Twelve ISSR primers produced a total of 100 fragments and 62 of them were polymorphic. The number of average polymorphic fragments per primer was 5.2. The mean polymorphism information content (PIC) was 0.37. The unweighted pair group method arithmetic average (UPGMA) analysis demonstrated that the accessions had a similarity range from 0.79 to 1.00. The accessions were separated into two main clusters; group A with five pummelos and group B with grapefruits. In the pummelo cluster, all pummelos were distinguished whereas in the grapefruit cluster some accessions were not clearly separated. There was a low level of variation in the grapefruits due to their mutation origin.

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.