Determination of Field Performance and Molecular Discrimination of Clementine Mandarin Selections

Clementine (Citrus clementina) is one of the most important mandarins with high yield and good fruit quality. Actually Clementine may be considered as a group instead of only one cultivar because of many Clementine clones exist in the world. Also it has been cultivated for a long time in Turkey, and therefore variations for agronomical traits are likely among cultivated Clementines due to bud mutations and hybridizations. The objectives of this study were to determine variations for some selected agronomical traits and genetic markers among 6 new Clementine clones ('A-21', 'A-67', 'A-68', 'A-82', 'A-90' and 'D-22') derived from selections. Tree growth, yield, fruit quality, and molecular discrimination of these clones were determined. After four years of evaluation, 'D-22' indicated the highest canopy volume. For yield per tree, the best clone was also 'D-22'. The highest fruit weight obtained from 'A-82'. Among the clones 'A-21' contained the lowest seed number and the highest total soluble solids/total acidity ratio. Molecular analysis, as assessed with 12 inter-simple sequence repeats (ISSR) primers, indicated that selections were separated with markers. Similarity values among the Clementine selections were between 0.97 and 1.00. According to our results low level of genetic diversity was determined among selections and it can be concluded that variations in orchards are abundant and mainly due to mutations

Production and quality of pollen in terms of fruit set on some self-pollinated pomegranate cultivars

Pomegranate is well-adapted fruit species to arid and semi-arid conditions. This species have male (A type - unfertile) and hermaphrodite flowers (B type - fertile) on the same plant. Because of several problems, appear for fertilization and fruit set, researches on pollen quality and fruit set may be essential. In the present study pollen viability, germination, pollen quantity of A and B type flowers of seven pomegaranate cultivars were investigated. Pollen viability assessment was carried out using 1% 2, 3, 5 triphenyl tetrazolium chloride (TTC) test. Pollen germination capability was investigated agar in petri method by using four different media. Pollen production per anther and per flower was assayed by Hemacytometric method. In addition, fruit set of these cultivars under self-pollination condition was determined. The highest pollen viability level obtained from 'Mayhos VIII' and 'Hicaz' cultivars. Pollen germination was assayed using 1% agar and different sucrose concentrations (5, 10, 15 and 20%). In general, 15% and 20% sucrose concentrations determined as the best germination medium. Anther number per flower ranged between 275 and 410 according to the cultivars. 'Katirbasi' had the highest pollen number per flower whereas 'Cevlik' had the lowest. Self-pollination of "Hicaz" with B type flowers showed the best fruit set. Besides, "Eksi Goknar" did not provide any fruit on self-pollination treatments. For that reason, this cultivar can determine as self-incompatible. This study showed that, some cultivars need pollinators to set fruit and this should be considered for new plantations

RESPONSE OF CITRUS ROOTSTOCKS TO DIFFERENT SALINITY LEVELS FOR MORPHOLOGICAL AND ANTIOXIDATIVE ENZYME ACTIVITES

ABSTRACT Citrus is the most produced fruit crop and often constrained by salinity due to their geographic distribution. We investigated morphological and antioxidave enzyme responses of six different citrus rootstocks under various NaCl concentrations, including Cleopatra mandarin (Citrus reshni Tan.), sour orange (C. aurantium L.), rough lemon (C. jambhiri Lush.), Volkamer lemon (C. volkameriana Tan & Pasq.), Carrizo citrange (Poncirus trifoliata L. Raf. X C. sinensis L. Osbeck) and trifoliata orange (P. trifoliata Raf.). Morphological and antioxidative enzyme responses of plants grown in hydroponic media containing 0, 45, 90 and 135 mM of NaCl were assessed at day 10, 20, 30, and 40. The highest shoot growth was observed in Cleopatra mandarin whereas trifoliata orange had the lowest shoot growth. Carrizo citrange showed the lowest visible leaf symptoms among the rootstocks and rough lemon produced the highest level of root biomass. A rootstock x NaCl dose x exposure time interaction was detected for enzymatic responses. In general, ascorbate peroxidase (APX; EC: 1.11.1.11) and guaiacol peroxidase (GP; EC: 1.11.1.7) activity in the rootstocks increased with the elevated salt level. Superoxide dismutase (SOD; EC: 1.15.1.1) activity was lowered in leaves of the rootstocks subjected to higher NaCl concentrations. In conclusion, this study indicated complexity of salt tolerance mechanism probably due to complex genetic make-up of the citrus rootstocks used and importance of APX and GP in salt tolerance of Citrus

Peroxidase gene-based estimation of genetic relationships and population structure among Citrus spp. and their relatives

Many stress-related interactions such as pathogen infection, insect tolerance, salt tolerance, auxin degradation, cell wall lignification, tissue suberization, and plant senescence involve various isoforms of peroxidases. Peroxidase gene polymorphism (POGP) markers have been used to estimate diversity, relationships and population structure among 80 Citrus and their relatives in Aurantioideae by using unweighted pair group method arithmetic average (UPGMA) and bayesian substructuring analysis. Fourteen primers produced a total of 148 fragments and 147 of them were polymorphic. The UPGMA analysis demonstrated that the accessions had a similarity range from 0.27 to 0.98 and were distinguished. The results of this study were mostly consistent with previous reports of different marker systems, but few different findings were also detected. The subtribe Clauseninae (tribe Clauseneae) did not clearly separate from the subtribes of the tribe Citreae. Substructuring analysis indicated that there were six subpopulations among the accessions studied. This study revealed that the POGP markers can be utilized to estimate genetic diversity, relationships and population structure in Citrus and related species in the Aurantioideae subfamily. © 2014, Springer Science+Business Media Dordrecht

Investigation of genetic relationships among trifoliata oranges and their hybrid relatives based on ISSR markers

Diversity and genetic relationships were investigated in 19 trifoliata oranges [(Poncirus trifoliata (L.) Raf] and their 27 hybrids including 20 citranges (P. trifoliata X Citrus sinensis), five citrumelos (P. trifoliata X C. paradisi) and two citremons (P. trifoliata X C. limon) based on intersimple sequence repeat (ISSR) markers. Twelve ISSR primers produced a total of 120 fragments and 82 of them were polymorphic (68%). The unweighted pair group method arithmetic average (UPGMA) analysis as assessed with ISSR data demonstrated that the accessions had a similarity range from 0.67 to 1.00. In the dendrogram there were three main groups including trifoliata, citremon and citrange-citrumelo groups. The trifoliata orange, citrange, citrumelo and citremon groups were separated. The citrumelo group was nested in the citrange branch. Genetic diversity among the trifoliata accessions was low probably because of their mutation origin. However all trifoliata accessions were distinguished except for two of them. The citrange group had higher polymorphism than the other trifoliata hybrids. Our study indicated that ISSR markers were useful to determine genetic diversity of related citrus groups such as trifoliata oranges and their intergeneric hybrids. © 2011 University of Bucharest

Characterization for yield, fruit quality, and molecular profiles of lemon genotypes tolerant to 'mal secco' disease

'Mal secco' is a serious disease of lemon and other citrus species, reduces lemon production, and limits the use of susceptible cultivars especially in the Mediterranean countries, against which there is no effective management system to control the disease. The objective of this study was to determine yield efficiency, tree and fruit characters, and molecular profiles of the selected promising genotypes in lemon breeding program to develop 'mal secco' tolerant lemon cultivars. After 4 years of evaluation, 'Tuzcu 894', a progeny of 'Finike Yerli Yuvarlak' and 'Kutdiken', was designated as promising genotype with high yield, fruit weight, juice content and low seed number contrary to 'Kutdiken' as control. 'Tuzcu 8911' was suitable for dense planting having the highest yield in CV. In addition, these two promising genotypes survived after many years being subjected to artificial and natural P. tracheiphila infections and harsh winter temperatures, which were attractive to the citrus industry. Molecular analysis, as assessed with 11 inter-simple sequence repeats (ISSR) primers, indicated that 'Tuzcu 09 Aklimon' and its selections, 'Tuzcu 896', 'Tuzcu 897' and 'Tuzcu 898', were distinct from the other genotypes with similarity value of 0.82. Genetic variation among the other lemon genotypes was low and some of the genotypes were identical. It was concluded that variations in the agronomical characters are mainly due to mutations. © 2009 Elsevier B.V. All rights reserved

Genetic diversity and relationships of clementine mandarin accessions as assessed using SRAP markers

Diversity and relationships in 42 Clementine mandarins were analysed by using SRAP markers. Using 21 SRAP primer combinations 125 bands were obtained, of which 5 bands were polymorphic (4%). Genetic relationships estimated using simple matching coefficient and similarities of Clementines was very high (0.96-1.00). Dendrogram was separated into two clusters except one accession according to geographic origin. First cluster included Clementine accessions that selected from Turkey. Six of seven Clementines that Turkey origin were identical. Second cluster included 35 Clementines and 34 of them were identical