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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Na uptake was superior on the other rootstocks. It was observed that 'Carrizo' and 'Troyer' citrange rootstocks had advantages over sour orange in nutrient uptake. Thus, growth performance, yield, and quality parameters considered, 'Carrizo' and/or 'Troyer' citranges could be suggested as rootstocks for the studied mandarin cultivars under similar ecological conditions.

The plant growth, yield, yield efficiency, and fruit quality of 'Rhode Red Valencia' and 'Valencia Late' sweet oranges (Citrus sinensis (L.) Osbeck) on three rootstocks were evaluated under Eastern Mediterranean climatic conditions of Dörtyol-Hatay, which is one of the oldest and largest citrus and mandarin (Citrus reticulata Blanco) production regions in Turkey. The fruit yield was affected by rootstock in both scion cultivars from 2007 through 2010. Trees on 'Troyer' citrange had lower yield than those budded on the other rootstocks. The yield of 'Rhode Red Valencia' and 'Valencia Late' orange trees on 'Carrizo' citrange were about 9% and 19% more than those on 'Troyer' citrange, respectively. But trees on 'Troyer' citrange had significant higher yield efficiency than trees on sour orange and 'Carrizo' citrange, because of canopy volume of 'Troyer' citrange was lower than the other rootstocks. The heaviest fruits of 'Valencia Late' orange trees were harvested from 'Carrizo' citrange (214.69 g), while 'Rhode Red Valencia' orange trees did not show differences regarding the rootstock. The rootstocks had no significant effects on juice content of 'Rhode Red Valencia' and 'Valencia Late' oranges. The effects of the rootstocks in both scion cultivars on juice content, total acids (TA), Brix:TA ratio, and number of seeds per fruit were found to be insignificant.

In this research, the effects of rootstocks on the storage performance of Nova mandarins grafted on Carrizo citrange, Troyer citrange, or sour orange grown in the ecological conditions of Dörtyol were studied. Fruits were harvested at optimum maturity and kept at 4 °C and 6 °C for 120 days. Changes in weight loss, incidence of fungal decay and physiological disorders, juice content, total soluble solids (TSS), percent fruit with green button, titratable acidity (TA), juice pH, vitamin C content, and rind color (L*, C*, h°) were monitored at 15-day intervals during storage to determine the effects of rootstock on postharvest quality of Nova mandarins. The fruit of Nova mandarin grafted on sour orange and Carrizo citrange had higher weight loss than Troyer citrange. Weight loss from Nova mandarins kept at 4 °C and 6 °C reached 7.71% and 12.21%, respectively, after 120 days of storage. Juice pH, incidence of fungal decay, and physiological disorders increased, while juice content, TA, vitamin C content, percent fruit with green button, and L*, C*, and h° values of rind color decreased in the Nova mandarin cultivar during cold storage. According to the data, the fruits of Nova mandarin grafted on Carrizo citrange, Troyer citrange, or sour orange were stored better at 4 °C than 6 °C. Fruit could be kept at 4 °C for 75 days and at 6 °C for 45 days without any quality deterioration.