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This study has been conducted to determine the fruit quality parameters such as sugar and carotenoid content as well as plant and fruit characteristics of 11 local watermelon genotypes from watermelon genetic resources collection of Cukurova University, Department of Horticulture. First and 50% male and female flowering period, main stem length, main stem diameter, number of nodes on main stem, total yield, fruit weight, fruit length, fruit diameter, fruit rind thickness, total soluble solids (TSS), sugar and carotenoid contents were examined. Although there is no significant difference for main stem diameter and number of nodes on the main stem, significant differences were obtained for total yield, sugar and carotenoid composition of the genotypes. Carotenoid and sugar analysis were performed with a high-performance liquid chromatographic method coupled with diode-array detector (HPLC-DAD) and HPLC coupled with refractive index detector (RID), respectively. In all studied genotypes, cis-13-lycopene and β-carotene were the most abundant compounds. As expected for watermelon genotypes, the main sugar found in all studied genotypes was fructose. According to PCA analyses, genotypes were characterized by physical and chemical composition. Overall evaluation of results revealed that Kar 147 had better potential with carotenoid, sugar contents and fruit characteristics.

In the study, two commercial Cucurbita maxima×Cucurbita moschata hybrid (Nun9075 and TZ148), Lagenaria spp. hybrid (Argentario) and one local Lagenaria spp. genotype (3335) and one Citrullus amarus genotype (PI 296341) were used as rootstocks. The male and female parents of two watermelon hybrids (187×125 and 11×162) were used as scions. Ungrafted plants formed the control group and also each parent was grafted on itself. Male parents were used for pollen measurements. Fruit weight, fruit height, fruit diameter, fruit rind thickness, total soluble solid content, total number of seeds, total seed weight and 1000 seeds’ weight and seed vigor tests were carried out in fruits of female parents crossed with male parents grafted onto the same rootstock. According to results of this study, the highest pollen production was obtained from Argentario while in terms of pollen germination and pollen viability there was no difference between applications in general. It was determined that grafting on Argentario and 3335 rootstocks increased fruit height, fruit diameter, fruit rind thickness, and the amount of total soluble solid, and the best performing rootstocks in terms of fruit weight were found to be Argentario, 3335, TZ148 and NUN9075. The highest seed number, seed weight and 1000 seeds weight were obtained from those grafted on TZ148 and NUN9075 rootstocks. Although variable results were obtained in terms of early germination, there was no rootstock that came to the fore in general. There was no difference between the rootstocks regarding accelerated aging test and controlled deterioration test.

Gummy stem blight (GSB), a major disease caused by Stagonosporopsis cucurbitacearum (syn. Didymella bryoniae), has caused significant losses of watermelon in the United States. The lack of progress in the development of resistant cultivars is the result of complex inheritance of resistance and breeding strategies that rely on single-plant selection. Because the sources of resistance are wild watermelon relatives, good fruit quality has been difficult to maintain during the selection process. Three hundred recombinant inbred line (RILs) in a population that carries resistance genes to GSB as well as good fruit quality were produced. This was accomplished by crossing and intercrossing resistant plant introductions, crossing the resulting progenies with elite cultivars, intercrossing those progenies, and, finally, self-pollinating to the S3 generation. The 300 RILs were evaluated for disease severity and fruit morphological and quality traits under greenhouse and field conditions in a randomized complete block design with 10 replications and 3 years. The means and correlations for disease severity ratings and fruit quality traits were estimated. Approximately 186 RILs had disease severity ratings below the mean value of the disease assessment scale (4.5), indicating that they possibly carry one or more genes for resistance to GSB. All disease severity ratings were correlated to each other (r = 0.67–0.98; P < 0.001), but they were not correlated with fruit quality traits. Most importantly, several resistant RILs showed good to excellent fruit quality. Our results provide evidence of improved germplasm with high resistance and good fruit quality.

International audience; Shapes of vegetables and fruits are the result of adaptive evolution and human selection. Modules controlling organ shape have been identified. However, little is known about signals coordinating organ development and shape. Here, we describe the characterization of a melon mutation rf1, leading to round fruit. Histological analysis of rf1 flower and fruits revealed fruit shape is determined at flower stage 8, after sex determination and before flower fertilization. Using positional cloning, we identified the causal gene as the monoecy sex determination gene CmACS7, and survey of melon germplasms showed strong association between fruit shape and sexual types. We show that CmACS7-mediated ethylene production in carpel primordia enhances cell expansion and represses cell division, leading to elongated fruit. Cell size is known to rise as a result of endoreduplication. At stage 8 and anthesis, we found no variation in ploidy levels between female and hermaphrodite flowers, ruling out endoreduplication as a factor in fruit shape determination. To pinpoint the gene networks controlling elongated versus round fruit phenotype, we analyzed the transcriptomes of laser capture microdissected carpels of wild-type and rf1 mutant. These high-resolution spatiotemporal gene expression dynamics revealed the implication of two regulatory modules. The first module implicates E2FDP transcription factors, controlling cell elongation versus cell division. The second module implicates OVATE-and TRM5-related proteins, controlling cell division patterns. Our finding highlights the dual role of ethylene in the inhibition of the stamina development and the elongation of ovary and fruit in cucurbits.

Bottle gourd [Lagenaria siceraria (Molina) Standl.] is widely produced in some Asian and African countries as a fresh vegetable as well as for seed consumption. A major use of bottle gourd is for rootstocks in grafted watermelon production. There are several centers where bottle gourd genetic resources are maintained, with the U.S. Department of Agriculture (USDA) germplasm collection being one of the most important. There is little published information on the relationship between seed morphology and the early establishment of seedlings in bottle gourd. The objective of this study was to determine seed characterization, morphology, and cotyledon shape in 163 Lagenaria spp. accessions and measure any relationship between seed and cotyledon characteristics. In USDA Lagenaria germplasm, it has been determined that the common character in seeds was medium in terms of seed size (53% of accessions), intermediate in seed surface lustre (39% of accessions), brown in seedcoat color (89% of accessions), thin and uniform in seed margin (35% of accessions), and tan in seed margin color (64% of accessions). According to the research results, seed weight ranged from 0.11 g (PI 500820) to 0.36 g (PI 675112), seed length from 13.17 mm (PI 500820) to 23.68 mm (PI 675112), and seed width from 5.86 (PI 500808) to 11.21 mm (PI 491274). Cotyledon length ranged from 5.46 cm (PI 368640) to 2.47 cm (PI 381850). The widest cotyledon was 3.00 cm (PI 534552), and the narrowest was 1.50 cm (PI 381831). Interesting correlations were observed for seed weight with seed length (R2 = 0.259), and cotyledon length with cotyledon width (R2 = 0.547).

Cucurbit plants usually are sensitive to chilling and easily damaged. Although bottle gourds, which are members of the Cucurbitaceae family, are considered as fresh vegetables in some Asian countries, their main use in recent years is to be used as rootstocks in grafted watermelon cultivation. We tested 163 bottle gourd accessions of the U.S. Department of Agriculture (USDA) genebank for cold tolerance in the early seedling stage. The experiment was conducted using controlled environment chambers with 3 chilling durations (36, 48, and 60 hours) at 4 °C. Chilling damage was rated 0 to 9 (0 = no damage, 1 to 2 = trace of damage, 3 to 4 = slight damage, 5 to 6 = moderate damage, 7 to 8 = advanced damage, 9 = plant totally dead). We rated damage separately for the cotyledons, true leaf, and growing point. Cold damage was higher at a chilling duration of 60 hours, and decreased at 48 and 36 hours. Most tolerant cultigens were PI 491272, PI 491280, PI 491281, PI 491286, and PI 491326. Most susceptible were PI 381845, PI 381846, PI 534556, PI 636137, and PI 668365.

In this study, 30 watermelon lines which were selected as a result of the data obtainedfrom the “Characterization of Post-Harvest Bioactive Properties of Watermelon Gene Pure Lines inAdvanced Breeding Programs” project were hybridized and hybrid seeds were obtained in 2016.These hybrid seeds were planted in an open field in 2017 and 2018 and harvested in July. In 2017, thevalues of L, a, b, C *, titratable acidity and pH values were found to be statistically insignificant whilethe value of ho was found to be significant. In 2018, L, a, b, C *, ho, and pH values were found to besignificant. Total carotenoid, lycopene and β-carotene values were found to be important in 2017,whereas in 2018, only β-carotene values were found to be significant. Ascorbic acid, total phenol,antioxidant activity, citrullin, pectin methylesterase, chitinase, fructose, glucose, sucrose and totalsoluble solid values of hybrids in 2017 and 2018 were found to be significant in both years., Bu çalışmada, “İleri Islah Programlarında Değerlendirmek Üzere Karpuz Gen HavuzundakiElit Saf Hatların Hasat Sonrası Biyoaktif Özelliklerinin Karakterizasyonu” projesinden elde edilenveriler sonucunda seçilen 30 adet karpuz hattı 2016 yılında melezlenmiş ve hibrit tohumlarıçıkarılmıştır. Bu hibrit tohumlar 2017 ve 2018 yıllarında açık araziye dikilmiş ve temmuz ayındahasatları yapılmıştır. 2017 yılında çeşitler arasında L, a, b, C*, titre edilebilir asitlik ve pH değerleriaçısından farklar istatistiki olarak önemsiz bulunurken, ho değeri önemli bulunmuştur. 2018 yılında iseL, a, b, C*, ho, ve pH değerleri önemli bulunmuştur. Toplam karotenoid, likopen ve β-karotendeğerleri açısından 2017 yılında hepsi önemli bulunurken, 2018 yılında ise sadece β-karoten değerleriaçısından önemli bulunmuştur. Hibritlerin 2017 ve 2018 yıllarındaki askorbik asit, toplam fenol,antioksidant aktivite, citrullin, pektin metilesteraz, kitinaz, fruktoz, glikoz, sakkaroz ve sudaçözünebilir kuru madde değerleri açısından her iki yılda da önemli bulunmuştur.

This study was carried out in the spring of 2019 and 2020. In the study, TZ148 and Nun9075 from Cucurbita maxima×Cucurbita moschata hybrid commercial rootstocks, hybrid rootstock Argentario and local genotype 3335 from Lagenaria spp., PI296341 from Citrullus amarus group and also self prafted plants of each line were used. The parents of 187×125 and 11×162 watermelon hybrids developed by Alata Horticultural Research Institute were used as scion. Ungrafted plants formed the control group. The research consists of two stages. At the first stage, all rootstocks were evaluated in terms of germination and emergence. In the second stage, including each rootstock within itself, effects on germination rate (%), average germination time (days), germination rate index, emergence rate (%), average emergence time (days) and emergence rate index were investigated on hybrid seeds obtained by pollination of female parent with pollens brought 1-from the male parent grafted on the same rootstock, 2-from the male parent grafted on itself and 3-from the ungrafted male-parent. Considering all the results obtained in both years, if all rootstocks are evaluated together and separately, no difference was found in terms of applications among total germination and emergence numbers. Although it varies from year to year and from combination to combination in terms of shortening the average germination time and consequently increasing the germination rate index, it can be said that the best results are obtained from those grafted on TZ148, and grafting on Nun9075 shortens the average emergence time., Bu çalışma 2019 ve 2020 yıllarının ilkbahar aylarında yürütülmüştür. Çalışmada; anaç olarak Cucurbita maxima×Cucurbita moschata melezi ticari anaçlarından TZ148 ve Nun9075, Lagenaria spp. anaçlarından Argentario hibrit anacı ve 3335 numaralı lokal genotip, Citrullus amarus grubundan PI296341 ve ayrıca her hat kendi üzerine aşılanarak kullanılmıştır. Kalem olarak ise Alata Bahçe Kültürleri Araştırma Enstitüsü tarafından geliştirilen 187×125 ve 11×162 karpuz hibritlerinin ebeveynleri kullanılmıştır. Aşısız bitkiler ise kontrol grubunu oluşturmuştur. Araştırma iki aşamadan oluşmaktadır. Birinci aşamada; bütün anaçlar kendi içerisinde çimlenme ve çıkış açısından değerlendirilmiştir. İkinci aşamada ise her ana ebeveyn her anaç kendi içerisinde olmak üzere; 1-aynı anaç üzerine aşılı baba ebeveynden, 2- kendi üzerine aşılı baba ebeveynden ve 3-aşısız baba ebeveynden getirilen çiçek tozları ile tozlanmış, elde edilen hibrit tohumlarda çimlenme oranı (%), ortalama çimlenme süresi (gün), çimlenme hız indeksi, çıkış oranı (%), ortalama çıkış süresi (gün) ve çıkış hız indeksi üzerine etkileri incelenmiştir. Her iki yılda da alınan bütün sonuçlar göz önünde bulundurularak; tüm anaçlar bir arada ve ayrı ayrı değerlendirilecek olursa toplam çimlenen ve çıkan sayıları bakımından uygulamalar arasında fark bulunamamıştır. Ortalama çimlendirme süresinde kısalma ve buna bağlı olarak çimlenme hız indeksini arttırma bakımından yıldan yıla ve kombinasyondan kombinasyona değişmekle beraber, genel olarak en iyi sonuçların TZ148 üzerine aşılananlardan alındığı, ayrıca Nun9075 üzerine aşılamanın ortalama çıkış süresini kısalttığı söylenebilir.

Under semi-arid soil conditions, soils are poor in nutrient availability due to the high clay and lime content and high pH; hence, mycorrhizal inoculation is a good strategy for sustainable agriculture. As it is still very difficult to produce a large quantity of mycorrhizal inoculum for a large area, it is reasonable to produce mycorrhizal-inoculated seedlings, which are then transplanted to the field. In order to investigate the effect of mycorrhizal inoculation (Glomus mosseae) techniques on plant yield and nutrient uptake of several horticultural plants, field experiments were conducted using a selected Menzilat soil series (Entic Chromoxerert), located in the Research Farm, Faculty of Agriculture, University of Cukurova, (eastern Mediterranean region) Turkey. Two growth pot sizes and two inoculation technique combinations consisting of six horticultural plants were replicated three times in a factorial randomized block design. The pure culture of G. mosseae was maintained and multiplied with sorghum under glasshouse conditions. Pepper, eggplant, tomato, cucumber, melon and watermelon seedlings were produced in different growth media, comprised of different composting material with several mycorrhizal species. Seedlings were produced using different techniques. Mycorrhizal-inoculated and non-inoculated seedlings were grown under field conditions using different inoculation techniques. The experiments revealed that under field conditions, mycorrhiza-inoculated seedlings are effectively established and result in high plant growth and yield. The results also revealed that for both techniques, plant yields were higher and mycorrhizal-inoculated plants produced more yield than non-mycorrhizal plants. The results showed that mycorrhizal-inoculated plants had higher P and Zn content than non-inoculated plants, but immersed mycorrhizal-inoculated plants had higher P concentration compared with granular application. We conclude that seedling quality is dependent on growth medium and mycorrhizal spore effectiveness. Furthermore, using mycorrhizal-inoculated seedlings appears to be a good strategy for horticultural production. © 2019 International Society for Horticultural Science. All rights reserved.

Bu çalışmada üç farklı Brüksel lahanası çeşidinin Çukurova Bölgesi koşullarında farklı zamanlarda ekimleri yapılarak bitki gelişimi, verim ve baş kaliteleri araştırılmıştır. Araştırmada Franklin Fı, Maximus Fı ve Divino Fı Brüksel lahanası çeşitlerinde 4 farklı ekim ve dikim zamanının aylık ölçümlerle bitki boyu (cm), ana gövde çapı (mm) ve yaprak sayısına (adet/bitki) etkileri ile verim (g/m2), baş ağırlığı (g), baş çapı (mm), baş yüksekliği (mm) ile içsel kalite parametreleri olan C vitaminine (mg/100 g), antioksidan kapasitesine [μmol trolox equivalents (TE)/g] ve toplam fenolik madde miktarına [mg gallik asit ekivalent (GAE)/100 g] etkileri incelenmiştir. Araştırma bulgularına göre; bitki boyu, ana gövde çapı ve yaprak sayısı açısından Maximus Fı çeşidi, diğer çeşitlere göre daha uzun, daha kalın ve daha fazla yapraklı olarak tespit edilmiştir. Verim açısından Maximus Fı çeşidinin (584,88 g/m2), diğer çeşitlerden (Franklin Fı ve Divino Fı‘de sırasıyla 367,97 g/m2 ve 259,82 g/m2) daha verimli olduğu kaydedilmiştir. Baş ağırlığı, baş çapı ve baş yüksekliği açılarından Maximus Fı çeşidinin, diğer Brüksel lahanası çeşitleri olan Franklin Fı ve Divino Fı çeşitlerinden daha üstün olduğu gözlenmiştir. Ekim zamanları değerlendirildiğinde; 1. dönemin, diğer dönemlere göre hem verim, hem de baş özelliklerinde daha elverişli olduğu kaydedilmiştir. C vitamini, antioksidan kapasitesi ve toplam fenolik madde miktarı içeriğinde ise Franklin Fı çeşidinin, diğer çeşitlere göre daha yüksek oranlara sahip olduğu, geç dikimlerin de daha fazla besin içeriğine sahip olduğu tespit edilmiştir.

Bu calismada, su kabagi anaclarinin karpuzun bitki besin elementi alimina ve azot kullanim etkinligine etkileri arastirilmistir. Kalem olarak kullanilan Crimson Tide karpuz [C itrullus lanatus (Thunb.) Mats. & Nak.] cesidi birisi koy cesidi (Birecik) ve dordu su kabagi ( Lagenaria siceraria ) melezi (Skopje, Emphasis, 216 and FRGold) olan anaclar uzerine asilanmistir. Asisiz Crimson Tide karpuz cesidi kontrol olarak kullanilmistir. Bitkiler dis kosullar uygun oluncaya kadar alcak plastik tunel altinda yetistirilmistir. Bitkiler 18 kg N da -1 , 20 kg P 2 O 5 da -1 ve 18 kg K 2 O da -1 olacak sekilde gubrelenmis, mikro element gubrelemesi yapilmamistir. Fosforun tamami taban gubresi olarak verilirken, N ve K uc esit parcaya bolunmustur. N ve K’ un ilk kismi taban gubresi olarak verilmis, ikinci kismi dikimden 20 sonra, ucuncu kisim ise dikimden 40 gun sonra verilmistir. Deneme tesaduf bloklari deneme desenine gore dort yinelemeli ve her yinelemede 15 bitki olacak sekilde kurulmustur. Bitkiler 200 x 50 cm mesafelerle dikilmis ve damla sulama yontemiyle sulanmistir. Bitki besin elementi analizleri surgun ucundan sonra tam gelismis yedi ve sekizinci yapraklarda yapilmistir. Asili ve asisiz bitkilerin yapraklarindaki N, P, K ve Ca acisindan bir fark bulunmazken, Mg icerikleri onemli farkliliklar gostermistir. Butun asili bitkiler asisiz bitkilerden daha fazla Fe icerigine sahip olurken, Cu ve Zn konsantrasyonlari anaca bagli olarak farklilik gostermistir. Asili bitkiler daha yuksek azot kullanim etkinligi ve verim degerlerine sahip olmuslardir. Bu calismada kullanilan anaclarin bitki besin elementi alimini tesvik ettigi, bitkisel gelisimi ve verimi artirdigi tespit edilmistir.

Doubled haploid (DH) technology is very advantageous in plant breeding. This technique is beneficial for reducing the time required to obtain pure lines and contributes to the selection efficiency. Using this technique, 100% homozygosity can be achieved in a single generation, while the development of stable lines using the traditional self-pollination method takes from 6 to 8 years. It has long been used in diverse crops including cucurbits. DHs can be obtained via parthenogenesis (pollination mostly with irradiated pollen), gynogenesis (in vitro culture of ovules and ovaries), and androgenesis (in vitro culture of microspores and anthers). All these methods have been used for over 30 years to develop haploid and DH lines in cucurbit crops. Nowadays, many researchers benefit from these techniques routinely. However, there are still many limits for using DH technology in watermelon breeding programmes. The number of developed DH lines is still very low.In this chapter, we present a protocol based on the different studies on haploids and DHs induced in watermelon through irradiated pollen technique, unfertilized ovule/ovary culture and anther/microspore culture. According to the results of all these studies, it is crucial to develop an efficient protocol for haploid embryo induction to enhance the frequency of obtaining haploid embryos in watermelon.

Doubled haploid (DH) technology is very advantageous in plant breeding. This technique is beneficial for reducing the time required to obtain pure lines and contributes to the selection efficiency. Using this technique, 100% homozygosity can be achieved in a single generation, while the development of stable lines using the traditional self-pollination method takes from 6 to 8 years. It has long been used in diverse crops including cucurbits. DHs can be obtained via parthenogenesis (pollination mostly with irradiated pollen), gynogenesis (in vitro culture of ovules and ovaries), and androgenesis (in vitro culture of microspores and anthers). All these methods have been used for over 30 years to develop haploid and DH lines in cucurbit crops. Nowadays, many researchers benefit from these techniques routinely. However, there are still many limits for using DH technology in watermelon breeding programmes. The number of developed DH lines is still very low.In this chapter, we present a protocol based on the different studies on haploids and DHs induced in watermelon through irradiated pollen technique, unfertilized ovule/ovary culture and anther/microspore culture. According to the results of all these studies, it is crucial to develop an efficient protocol for haploid embryo induction to enhance the frequency of obtaining haploid embryos in watermelon.

Developing drought-tolerant crops is an important strategy to mitigate climate change impacts. Modulating root system function provides opportunities to improve crop yield under biotic and abiotic stresses. With this aim, a commercial hybrid tomato variety was grafted on a genotyped population of 123 recombinant inbred lines (RILs) derived from Solanum pimpinellifolium, and compared with self- and non-grafted controls, under contrasting watering treatments (100% vs. 70% of crop evapotranspiration). Drought tolerance was genetically analyzed for vegetative and flowering traits, and root xylem sap phytohormone and nutrient composition. Under water deficit, around 25% of RILs conferred larger total shoot dry weight than controls. Reproductive and vegetative traits under water deficit were highly and positively correlated to the shoot water content. This association was genetically supported by linkage of quantitative trait loci (QTL) controlling these traits within four genomic regions. From a total of 83 significant QTLs, most were irrigation-regime specific. The gene contents of 8 out of 12 genomic regions containing 46 QTLs were found significantly enriched at certain GO terms and some candidate genes from diverse gene families were identified. Thus, grafting commercial varieties onto selected rootstocks derived from S. pimpinellifolium provides a viable strategy to enhance drought tolerance in tomato., This research was funded by the Spanish Government (Ministerio de Ciencia e Innovación), grant numbers AGL2014-56675-R and AGL2017-82452-C2-2-R, and the European Union (FP7-KBBE-2011-5 contract number 289365 (ROOTOPOWER))and (H2020 SFS-28-2020 contract number 101000716 (HARNESSTOM)).

Kavunlarda hibrit tohum üretiminde zaman, işgücü ve verim kaybının önüne geçmek için andromonoik ana materyalde erkek kısırlık ya da erkek kısırlığa sebep olacak kimyasal hibridizasyon ajanları (KHA) kullanımı önem taşımaktadır. Bu çalışmada bazı bitki türlerinde KHA olarak kullanılan ABA hormonunun Galia Fı kavun çeşidinde bitki gelişmesi, erkek çiçek oluşumu ve çiçek tozu kalitesi üzerine etkileri araştırılmıştır. Araştırmada ABA‘nın 250 ve 500 ppm‘lik iki dozu, fidelikte (F), serada ilk çiçeklenme döneminde askıya alınmış bitkilerde (İÇ) ve fidelik+ilk çiçeklenme dönemlerinde (F+İÇ) uygulanmıştır. Kontrol uygulamasındaki bitkilere ise sadece su püskürtülmüştür. Araştırma bulgularına göre, ABA‘nın 500 ppm‘lik dozunun F+İÇ ile F uygulamaları bitki gelişimini başlangıçta biraz baskılamış olmakla birlikte, sıcaklıkların yükselmesi ile bu etki ortadan kalkmıştır. ABA uygulamaları erkek çiçeklerin açmasını engellememiş olmakla beraber, erkek çiçek sayısı 500 ppm F+İÇ uygulamasında kontrole göre %62 oranında azalmıştır. Çiçek tozu canlılık ve çimlenmesi üzerine de ABA uygulamalarının kaliteyi arttırıcı bir etkisi olmamakla birlikte, canlılık ve çimlenme oranlarının %95‘in üzerinde olduğu tespit edilmiştir.

In this study,rootstock effects of bottle gourds on nutrient uptake and nitrogen useefficiency of watermelon were investigated. Watermelon seedlings were graftedonto Birecik, Skopje, Emphasis, 216 and FRGold. Non-grafted plants were used ascontrol. The seedlings were transplanted and kept under plastic tunnel untilclimatic conditions were suitable for watermelon cultivation. Experimental areawas amended with doses of 18 kg N da-1,20 kg P2O5da-1 and 18 kg K2O da-1based on soil analysis. No micro-nutrientfertilizer was applied. While total P and 1/3 of N and K were applied as basefertilizer before transplanting, the second and third portions of the N and Kwere applied 20 and 40 days after transplanting, respectively. The experimentplanned as a completely randomized block design and repeated four times, eachreplication has 15 plants. The seedlings were transplanted with 200 x 50 cm spacing. Macro andmicro-nutrient contents were analyzed in fully grown seventh and eighth leavesfrom soot tips. While N, P, K and Ca contents of the leaves did not showsignificant differences between graft combinations and control plants, Mg concentrationwas significantly affected by rootstocks. All graft combinations had higher Feconcentration in the leaf than non-grafted plants. Cu and Zn concentrationsshowed significant variation based on rootstock. Higher nitrogen use efficiency(ton yield kg N-1) was recorded in all graft combinations ascompared to controls. Bottle gourd rootstocks used in this study enhanced thenutrient uptake, plant growth and total fruit yield., Bu çalışmada, su kabağı anaçlarının karpuzunbitki besin elementi alımına ve azot kullanım etkinliğine etkileriaraştırılmıştır. Kalem olarak kullanılan Crimson Tide karpuz [Citrulluslanatus (Thunb.) Mats. & Nak.] çeşidi birisi köy çeşidi (Birecik) vedördü su kabağı (Lagenaria siceraria) melezi (Skopje, Emphasis, 216 and FRGold) olan anaçlar üzerineaşılanmıştır. Aşısız Crimson Tide karpuz çeşidi kontrol olarak kullanılmıştır.Bitkiler dış koşullar uygun oluncaya kadar alçak plastik tünel altındayetiştirilmiştir. Bitkiler 18 kg N da-1, 20 kg P2O5da-1 ve 18 kgK2O da-1 olacak şekilde gübrelenmiş, mikro elementgübrelemesi yapılmamıştır. Fosforun tamamı taban gübresi olarak verilirken, Nve K üç eşit parçaya bölünmüştür. N ve K’ un ilk kısmı taban gübresi olarakverilmiş, ikinci kısmı dikimden 20 sonra, üçüncü kısım ise dikimden 40 günsonra verilmiştir. Deneme tesadüf blokları deneme desenine göre dört yinelemelive her yinelemede 15 bitki olacak şekilde kurulmuştur. Bitkiler 200 x 50 cmmesafelerle dikilmiş ve damla sulama yöntemiyle sulanmıştır. Bitki besinelementi analizleri sürgün ucundan sonra tam gelişmiş yedi ve sekizinciyapraklarda yapılmıştır. Aşılı ve aşısız bitkilerin yapraklarındaki N, P, K veCa açısından bir fark bulunmazken, Mg içerikleri önemli farklılıklargöstermiştir. Bütün aşılı bitkiler aşısız bitkilerden daha fazla Fe içeriğinesahip olurken, Cu ve Zn konsantrasyonları anaca bağlı olarak farklılıkgöstermiştir. Aşılı bitkiler daha yüksek azot kullanım etkinliği ve verimdeğerlerine sahip olmuşlardır. Bu çalışmada kullanılan anaçların bitki besinelementi alımını teşvik ettiği, bitkisel gelişimi ve verimi artırdığı tespitedilmiştir.

This research was conducted to investigate rootstock effects on seed yield and quality in watermelon. The work was conducted in the experimental fields and laboratories of the Department of Horticulture of the University of Cukurova in the 2016 and 2017 growing seasons. Watermelon cv. Crimson sweet (CS) scion was grafted onto three different rootstocks (Cucurbita ‘NUN-9075’, Lagenaria ‘Argentario’, and citron watermelon ‘PI296341’). Plants were assessed according to their main stem length, main stem diameter, number of nodes, biomass, pollen production and development, fruit yield and quality, and seed yield and quality. NUN-9075/CS and Argentario/CS graft combinations resulted in higher average stem length, plant biomass, fruit yield and quality, seed yield, seed emergence, and germination percentage. There was no significant difference observed between graft combinations in pollen viability, pollen germination, and normal pollen production. No significant difference was observed between graft combinations in accelerated ageing (AA), and the seed germination decreased after AA of 192 h. In the second year (2017), there was higher main stem length, main stem diameter, total fruit yield, seed yield, and number of seeds per fruit compared to the first year (2016). Based on the results of this study, NUN-9075 rootstock performed better than other rootstocks; hence, it is recommended as the best rootstock. © 2019, The Author(s). Firat University Scientific Research Projects Management Unit Acknowledgements This study was supported by Cukurova University Scientific Research Project Unit (Grant No. FDK-2016-6465) (Bilimsel Araştırma Projesi—BAP). We also thank Antalya seedling Company for providing seeds and seedlings production. Indebted thanks to Ph.D. and M.Sc. students who helped during field and laboratory work.

The genetic diversity of Turkish watermelon genotypes selected from the watermelon genetic resource collection was evaluated by simple sequence repeat (SSR) and sequence-related amplified polymorphism (SRAP) markers. Most of the accessions were collected from various geographical regions of Turkey. Different Citrullus species, wild relatives, foreign landraces, open pollinated (OP), and commercial hybrid cultivars were also assessed for genetic relatedness. Fourteen SSR primers and 31 SRAP primer combinations were used in the experiment. Both SSR markers (100%) and SRAP markers (97.3%) generated high polymorphisms. Based on the SSR and SRAP data, the genetic similarity coefficients were calculated, and dendrograms were constructed using the unweighted pair-group method with arithmetic average (UPGMA). Cluster and principle coordinate analyses indicated that Citrullus lanatus var. Lanatus subspecies genotypes collected from the different regions of Turkey were closely genetically related. Overall, our results displayed low genetic variability within the Turkish watermelon germplasm in contrast with their high morphological diversity.

Genetic studies of watermelons [Citrullus lanatus (Thunb.) Matsum. & Nakai] sampled from Turkey, the second leading producer, may provide valuable information for breeding and research programs. The objectives of this study were to estimate the level of genetic diversity, population structure, and optimum genome sampling size among the Turkish and several introduced watermelons. From the collection, 256 watermelon lines representing all watermelon-growing areas of Turkey along with two accessions of a related genus (Praecitrullus fistulosus (Stocks) Pangalo) and a few popular cultivars were genotyped using sequence-related amplified polymorphism (SRAP) markers. Twenty-seven primers generated 210 molecular markers for genetic analyses. The unweighted pair group method with arithmetic average analysis produced no clear-cut pattern, while principal component analysis indicated three subgroups among the lines studied. They had a narrow genetic base within C. lanatus var. lanatus and were mostly distinguished from each other. Model-based structure analysis indicated that the number of subpopulations in watermelons was four. Among the 258 lines, only 20% (51 lines) had 0.80 or greater membership coefficients to one subpopulation, and therefore were not admixed. The remaining 207 were admixed by at least two subpopulations. The similarity matrix of genome sampling size of 40 randomly selected markers was highly correlated (r = 0.915) with the matrix of simple matching coefficients based on 100 markers, implying that 40 markers were detected to be sufficient for this species. Overall, this study concluded that the majority of the Turkish watermelons were distinguished from each other, difficult to classify, and admixed, with narrow genetic variation.

The aim of this study is to determine the effects of deficit irrigation on nitrogen consumption, yield, and quality in grafted and ungrafted watermelon. The study was conducted in Çukurova region, Eastern Mediterranean, Turkey, between 2006 and 2008, and employed 3 irrigation rates (full irrigation (I100) with no stress, moderate irrigation (DI70), and low irrigation (DI50); DI70 and DI50 were considered deficit irrigation) on grafted (CTJ, Crimson Tide+Jumbo) and the ungrafted (CT, Crimson Tide) watermelon. The amount of irrigation water (IR) applied to the study plots were calculated based on cumulative pan evaporation that occurred during the irrigation intervals. Nitrogen consumption was 16% lower in CTJ plants than in CT plants. On the other hand, consumption of nitrogen was 28% higher in DI50 plants than in DI70 plants while it was 23% higher in DI50 plants than in I100 plants. By grafting, the average amount of nitrogen content in seeds, pulps and peels for CTJ was 30, 43 and 56% more than those of CT, respectively. The yield and the quality were not significantly affected by the deficit irrigation. In this respect, grafting of watermelon gave higher yield, but, it had a slight effect on fruit quality. The highest yield values of 16.90 and 19.32 kg plant-1 in 2008 were obtained with I100 and in CTJ plants, respectively. However, DI50 treatment could be taken into account for the development of reduced irrigation strategies in semiarid regions where irrigation water supplies are limited. Additionally, the yield increased by applying CTJ treatment to the watermelon production. © 2015 Chinese Academy of Agricultural Sciences. Firat University Scientific Research Projects Management Unit: ZF2006D16, ZF2008BAP1 The authors would like to gratefully acknowledge the University of Çukurova, Turkey, for providing funding through the Scientific Research Projects of Çukurova University (ZF2006D16 and ZF2008BAP1). The authors thank to Dr. Elif UZ, Department of Molecular Biology and Genetics, for her help in preparing the manuscript.

The aim of this study was to evaluate different rootstocks for improving triploid seed production of the dessert watermelon, Citrullus lanatus. This 2-year study was conducted at two locations, in open fields at Antalya and Adana, Turkey, during the 2016 and 2017 growing seasons. The tetraploid watermelon line 'ST 101' was used as the female parent scion and the diploid line 'WL 92' as the male parent. Both parental lines were grafted onto three different rootstocks to determine the effect of grafting on seed yield and quality of triploid watermelon. Nun 9075, a Cucurbita interspecific hybrid (Cucurbita maxima × Cucurbita moschata), Argentario (Lagenaria siceraria), and citron watermelon PI 296341 (Citrullus amarus) were used as rootstocks. Nongrafted ST 101 and WL 92 were also crossed to be used as controls. The graft combinations and controls were compared for performance as measured by length, diameter and number of nodes of main stem, total yield, mean fruit weight, fruit length, fruit diameter, seed yield, number of seed per fruit, weight of 1000 seeds, seed germination and emergence percentage, days to germination and emergence, and seed coat and embryo weight ratio. Nun 9075/ST 101 and Argentario/ST 101 graft combinations resulted in longer main stems; increased total yield; heavier, longer, and wider fruits; and higher seed yield and number of seeds per fruit as compared to PI 296341/ST 101 graft combination and the controls in both locations and years.

WOS: 000449495500001 In this study, Nusem and Beppo snack seed pumpkin cultivars were used to determine the effects of different plant activators on seed protein, lipid and fatty acids contents. In the context of study, plant activators consist of Crop-set (CR), EM1, ERS, Vitormone-Plus Drip (VIT), Bacillus subtilis (OSU 142), Bacillus megatorium (M3), Azospirillum sp. (SP 245), Spirulina platensis (SIP), Ecocompost (EKO), Camli Botanica liquid organic fertilizer (BOT) and Zincon (ZIN) were used as organic fertilizer. In the experiment, the plant activators were applied to the plants alone or in combination with each other and organic fertilizer. Two separate control groups which were organic and conventional (CONV.) fertilizer have been identified. As a result of the use of different plant activators, the highest protein content was obtained from CONV. application (35.50%), M3+SP 245 (33.09%) and M3 (33.04%); the highest lipid content was observed from SP 245+OG (45.90%), CR (44.48%) and SIP+OG (44.26%) applications. The use of different plant activators effected the fatty acid contents of seeds. Total 11 fatty acids were identified. Among the fatty acids, C16: 0 (Palmitic acid), C18: 0 (Stearic acid), C18: 1 (Oleic acid) and C18: 2 (Linoleic acid) were found dominant. Cukurova University Scientific Research Projects UnitCukurova University [FDK-2015-3664] This project was funded by Cukurova University Scientific Research Projects Unit with the project code of FDK-2015-3664. The researcher thanks to Prof. Dr. Fikrettin Sahin from Yeditepe University, Turkey for providing isolates which are OSU 142, SP 245 and M3.

Molecular diversity and genetic relationships among the most typical Hungarian and Turkish melon accessions were analysed using SSR markers. Thirty melon accessions were characterized by 15 SSR primers. SSR primers generated a total of 69 bands across the 30 melon accessions, of which 66 were polymorphic. The sizes of the bands ranged from 112 to 237 bp. Accessions Kav 13 and Kav 173 showed the largest genetic distance, while the accessions Kav 30 and Kav 39 (two Kirkagac type accessions from different geographic origin) were the most similar genotypes in the germplasm. Based on the pair-wise genetic distances obtained by SSR marker results, Hungarian accession S6 showed 62% similarity with the Turkish genotype Kav 16 and 50% with Kav 13. A clustering dendrogram based on the genetic distance matrix was produced by NTSYS-PC. Accessions were divided into two main groups (I-II). There were three sub-clusters (SC) within the two groups, two in cluster I and one in cluster II. The obtained data showed that the investigated germplasm contained high genetic variability.

A total of 67 watermelon accessions which include 37 accessions from Korean and 27 accessions from Turkish germplasm and 3 accessions of other related species from USA were investigated for morphological characteristics. The UPOV descriptor list for 56 characters (6 seedlings, 4 plants, 11 leaves, 5 flowers, 23 fruits and 7 seeds) was used in characterization. In addition, eight quantitative characters, hypocotyl length, cotyledon width, cotyledon length, fruit weight, fruit length, fruit width, thickness of outer layer of pericarp and soluble solid content were also measured. The 56 qualitatively scored characters were analyzed by principle coordinate analysis (PCoA) while the eight quantitative ones were subjected to principle component analysis (PCA). Morphological characterization result demonstrated that the accessions displayed high morphological diversity(how much percent?). A high level of phenotypic diversity was observed from the results of morphological characterization. However, plant growth habit and leaf blade flecking showed constant characters for all of the accessions. The Korean and Turkish watermelon genotypes are diverse groups and can be separated by both multivariate analysis of morphological characters although the grouping was more apparent in PCoS results.

Plant peroxidases are a family of stress-related proteins possessing highly conserved domains, which previously allowed to develop peroxidase gene polymorphism (POGP) markers. Diversity, population structure and linkage disequilibrium (LD) based on POGP markers among 256 watermelons [Citrullus lanatus (Thunb.) Matsum. and Nakai] genotypes along with two outgroups were evaluated by using 14 peroxidase gene-specific primers and several statistical procedures. Ratio of polymorphism of POGP markers was high (98%). The unweighted pair-group method arithmetic average (UPGMA), neighbor-joining (NJ) and principle component analysis (PCA) indicated low level of genetic diversity and few geography-based clustering among the watermelon accessions. Substructuring Bayesian analysis revealed that there were three subpopulations among 258 watermelons. Analysis of molecular variance (AMOVA) indicated that 54% of the molecular variation resided within subpopulations, 39% within geographic origins and 7% among subpopulations. Linkage disequilibrium (LD) analysis indicated presence of LD among POGP loci. Overall, this study concluded that LD existed despite that it was variable among subpopulations, association studies were possible among watermelons, and substructuring analysis was efficient in analyzing population structure among watermelons. This study also indicated that the POGP markers would be useful for clarifying genetic parameters such as population structure and relationships among watermelons. (C) 2014 Elsevier B.V. All rights reserved.

Grafting is an alternative approach to reduce crop damage resulting from soil-borne pathogens. This approach also increases plant abiotic stress tolerance, which in turn increases crop yield and quality. Therefore, the objective of this study was to determine the effect of grafting on watermelon quality parameters with the use of different rootstock combinations. Different morphological characteristics (yellow-red fleshed, with seed-seedless, striped rind and dark green rind) were grafted on rootstocks of Argentario (Lagenaria spp.) and Maximus (Cucurbita maxima × C. moschata). While the highest fructose, sucrose and soluble solids content were measured in Argentario/ TP84, TP84 had the highest glucose content. Total carotenoids content in watermelons ranged from 15.36 ± 2.78 to 104.51 ± 12.04 mg kg-1. Argentario/ TP84 showed the highest level of lycopene (93.95 mg kg-1) among cultivars and combinations. ß-carotene content varied from 1.44 ± 0.01 to 3.76 ± 0.01 mg kg-1. The highest ascorbic acid content was in Argentario/ TP84 (17.26 mg kg-1), followed by Argentario/ 5299 (17.26 mg kg-1). Grafting significantly increased soluble solids, sugars (fructose, glucose and sucrose), total carotenoids and ascorbic acid contents. Maximus/ Ant09 had the highest total carotenoids and lycopene content but lowest fructose, sucrose and soluble solids content on C. maxima × C. moschata combinations, whereas Argentario/ TP84 has the highest fructose, sucrose, soluble solids, total carotenoids, ß-carotene, lycopene and ascorbic acid contents among cultivars and combinations. This study showed that use of bottle gourd (Lagenaria spp.) rootstock could enhance soluble solids, fructose, sucrose, lycopene and ascorbic acid contents in watermelon. © 2017, Horticulture Society of India. All rights reserved.

Developing more efficient tools for watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai) breeding programs may greatly contribute to genetic improvement. The aims of this study were to investigate genome-wide association analysis (GWAS), and to develop regression models for some important watermelon traits such as yield, fruit weight, flesh color, total soluble solid, seed coat color, seed length and flowering time using 96 lines selected from 258 pure lines. An initial analysis was conducted to reduce sample size to 96 in order to avoid identical, highly similar and distant relatives causing low level of polymorphism and rare alleles. These 96 lines were morphologically and genetically characterized for several morphological characters under the eastern Mediterranean conditions, Adana, Turkey and PCR-based molecular markers. Associated markers were estimated by TASSEL program based on general linear model and a regression model because each trait was established through backward regression procedure nested in the SAS program. Levels of variation explained by regression models were 41% with 6 markers for flesh color, 22% with 2 markers for fruit weight, 48% with 5 markers for total soluble solids, 21% with 6 markers for seed size, 9% with 4 markers for fruit flesh firmness, 39% with 6 markers for 50% flowering time. This first report of GWAS for the selected characteristics of watermelon indicated a great potential to increase the efficiency of breeding programs. © 2016 Elsevier B.V. Erciyes Üniversitesi: FBY-12-3838 110O104 This study was financially supported by the section of Scientific Research Unit of Erciyes University [ FBY-12-3838 ], and Turkish Scientific Council [ 110O104 ]. Some of the plant materials were kindly provided by Aegean Agricultural Research Institute (AARI), USDA-USA, INRA-France and Dr. Csaba ZSAMOSI, Budapest Corvinus University.

WOS: 000379533500016 PubMed ID: 27193591 Snake melon is an important cucurbit crop especially in the Southeastern and the Mediterranean region of Turkey. It is consumed as fresh or pickled. The production is mainly done with the local landraces in the country. Turkey is one of the secondary diversification centers of melon and possesses valuable genetic resources which have different morphological characteristics in case of snake melon. Genetic diversity of snake melon genotypes collected from different regions of Turkey and reference genotypes obtained from World Melon Gene Bank in Avignon-France was examined using 13 simple sequence repeat (SSR) markers. A total of 69 alleles were detected, with an average of 5.31 alleles per locus. The polymorphism information content of SSR markers ranged from 0.19 to 0.57 (average 0.38). Based on cluster analysis, two major groups were defined. The first major group included only one accession (61), while the rest of all accessions grouped in the second major group and separated into different sub-clusters. Based on SSR markers, cluster analysis indicated that considerably high genetic variability exists among the examined accessions; however, Turkish snake melon accessions were grouped together with the reference snake melon accessions. Scientific Research Projects Coordination Unit of Cukurova UniversityCukurova University [FBA-2014-2380] This research was supported by the Scientific Research Projects Coordination Unit of Cukurova University (FBA-2014-2380). The authors are grateful to Dr. Aydin Uzun for his kindly help in the PIC analysis; AARI, TAEA, EMTZARI, INRA (Michel Pitrat), and Veysel Aras for seed supplying.

A total of 58 Cucumis melo accessions were studied to compare the morphological characteristics of Hungarian and Turkish germplasm, including typical landraces as well as melons from gene banks of various origins. Hungarian and Turkish accessions representing the particular regions considered to have variation were selected. Qualitative characters were obtained according to the modified UPOV descriptor list for 70 characters. Seventeen quantitative characters (3 seedling, 3 leaf, 2 flower, 9 fruit) were also measured. The results indicated that both Hungarian and Turkish germplasm resources present wide range of diversity for morphological traits. The results also yielded significant findings as to choose the precious accessions for further breeding programs. Results of both qualitative and quantitative measurements indicated that accessions of the two countries are generally different. However, within the inodorus group very close relations were detected with multi-variable analyses. © 2009 Elsevier B.V. All rights reserved. Researchers are grateful to the Scientific and Technological Research Council of Turkey (TÜBİTAK) and its grant program “2216-Research Fellowship for Foreign Country Citizens”. In addition, authors thank Michel Pitrat from INRA, France for his assistance in seed supply and Dr. Sedat Serçe for his kind help for the statistical analyses of this research.

Genetic diversity of the Turkish watermelon genetic resources was evaluated using different Citrullus species, wild relatives, foreign landraces, open pollinated (OP) and commercial hybrid cultivars by RAPD markers. The germplasm was consisted of 303 accessions collected from various geographical regions. Twenty-two of 35 RAPD primers generated a total of 241 reproducible bands, 146 (60.6%) of which were polymorphic. Based on the RAPD data the genetic similarity coefficients were calculated and the dendrogram was constructed using UPGMA (Unweighted pair-group method with arithmetic average). Cluster analysis of the 303 accessions employing RAPD data resulted in a multi-branched dendrogram indicating that most of the Turkish accessions belonging to var. lanatus of Citrullus lanatus (Thunb.) Matsum et Nakai were grouped together. Accessions of different Citrullus species and Praecitrullus fistulosus (Stocks) Pangalo formed distant clusters from C. lanatus var. lanatus. Among 303 accessions, a subset of 56 accessions was selected representing different groups and a second dendrogram was constructed. The genetic similarity coefficients (GS) within the Turkish accessions were ranged from 0.76 to 1.00 with 0.94 average indicating that they are closely related. Taken together, our results indicated that low genetic variability exist among the watermelon genetic resources collected from Turkey contrary to their remarkable phenotypic diversity. © 2010 Springer Science+Business Media B.V. TOVAG 104O073 Acknowledgments The authors are grateful to the Council of Scientific and Technological Research of Turkey for the financial support (Project No: TOVAG 104O073). In addition, authors thank Dr. Sedat Serce for his kindly help for the statistical analyses of this research.

The aim of this study was to determine some morphological characters and genetic relations of indeterminate green bean accessions having different seed coat color collected from the Black Sea region of Turkey. In this research, a total of 39 green bean accessions and one kidney bean accession consisting of different main seed coat colors (white, black, yellow, green, brown, red, and dark red) and mixed seed coat colors were used. Plants were produced under greenhouse conditions for morphological characterization. We used 43 morphological characters described by UPOV for indeterminate green bean. In molecular analysis, the sequence-related amplified polymorphism (SRAP) marker system was used. A total of 21 primer combinations produced 138 bands. DNA band profiles were analyzed by NTSYS and a UPGMA dendrogram was generated. The total polymorphism rate was found to be 85.5%. According to research results, indeterminate green bean accessions showed a high level of morphological variation; however, narrow genetic diversity was detected based on molecular analysis.

In vivo induction of parthenogenesis using an irradiated pollen technique provides successful results in melon and accelerates breeding by shortening the time for obtaining 100% homozygous lines. Gamma rays (cobalt-60) are usually used for the pollen irradiation, although it is difficult to find a suitable source for irradiation. Haploid technology is widely used in melon breeding programs, so there is a need to find alternative sources for pollen irradiation. This study was performed to compare the efficiency of different irradiation sources to induce haploid embryos. One dose of cobalt-60 (300 Gy), two different doses (200 Gy and 300 Gy) of cesium-137, and two different doses (200 Gy and 300 Gy) of X-ray were used for the irradiation of melon pollen. All irradiation sources were efficient for fruit set, while the highest fruit set (60.38%) was obtained from 200 Gy cesium-137 and the lowest (20.01%) was obtained from 300 Gy X-ray. A total of 2294 haploid embryos were rescued, of which 2052 regenerated into plants. The number of rescued haploid embryos per fruit ranged between 8.77 (300 Gy cobalt-60) and 4.23 (200 Gy X-ray). The highest regeneration rate of haploid embryos into plants was 92.56% (300 Gy cobalt-60) and the lowest was 61.86% (200 Gy cesium-137). © TÜBİTAK.

PubMedID: 27171236 Understanding the evolution of sex determination in plants requires the cloning and the characterization of sex determination genes. Monoecy is characterized by the presence of both male and female flowers on the same plant. Andromonoecy is characterized by plants carrying both male and bisexual flowers. In watermelon, the transition between these two sexual forms is controlled by the identity of the alleles at the A locus. We previously showed, in two Cucumis species, melon and cucumber, that the transition from monoecy to andromonoecy results from mutations in 1-aminocyclopropane-1-carboxylic acid synthase (ACS) gene, ACS-7/ACS2. To test whether the ACS-7/ACS2 function is conserved in cucurbits, we cloned and characterized ClACS7 in watermelon. We demonstrated co-segregation of ClACS7, the homolog of CmACS-7/CsACS2, with the A locus. Sequence analysis of ClACS7 in watermelon accessions identified three ClACS7 isoforms, two in andromonoecious and one in monoecious lines. To determine whether the andromonoecious phenotype is due to a loss of ACS enzymatic activity, we expressed and assayed the activity of the three protein isoforms. Like in melon and cucumber, the isoforms from the andromonoecious lines showed reduced to no enzymatic activity and the isoform from the monoecious line was active. Consistent with this, the mutations leading andromonoecy were clustered in the active site of the enzyme. Based on this, we concluded that active ClACS7 enzyme leads to the development of female flowers in monoecious lines, whereas a reduction of enzymatic activity yields hermaphrodite flowers. ClACS7, like CmACS-7/CsACS2 in melon and cucumber, is highly expressed in carpel primordia of buds determined to develop carpels and not in male flowers. Based on this finding and previous investigations, we concluded that the monoecy gene, ACS7, likely predated the separation of the Cucumis and Citrullus genera. © 2016 Boualem et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. European Research Council Agence Nationale de la Recherche Saudi Pharmaceutical Society: ANR-10-LABX-40 ANR-11-BSV7-0024 This work was supported by BAP department in INRA, the grant Program Saclay Plant Sciences (SPS, ANR-10-LABX-40) for ABo and ABe, the Agence Nationale de la Recherche grant MELODY (ANR-11-BSV7-0024) for ABo, ABe and CD and the European Research Council grant (ERC-SEXYPARTH) for ABe. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We thank P. Audigier and N. Giovinazzo for plant care and V. Rittener for technical assistance. We thank M. Chatterjee for helpful discussions on the manuscript. We thank J. Fauve for providing watermelon andromonoecious accessions. This work was supported by BAP department in INRA, the grants Program Saclay Plant Sciences (SPS, ANR-10-LABX-40), ANR MELODY (ANR-11-BSV7-0024) and the European Research Council (ERC-SEXYPARTH).

The optimization of regeneration protocol for different genotypes increases the yield in transformation studies. Cotyledon explants of watermelon [Citrullus lanatus (Thunb) Matsum & Nakai] cv Crimson Sweet were cultured on MS medium containing combinations of benzyl adenine (BA) (0, 5, 10, 20 µM) and indole-3-acetic acid (IAA) (0, 0.5, 5 µM). Maximum shoot growth and subsequent rooting from explants on regeneration medium were obtained from the media containing 10 µM BA + 0.5 µM IAA and 20 µM BA (75 and 78%) by direct organogenesis, respectively. Histological analysis showed that cell division was observed in the epidermal and subepidermal layers. Protuberant structures were observed in tissues between 7 and 12 days in culture. Meristematic structures were observed after 12days in culture which later developed into buds.

The potential of grafted watermelon for resistance to Fusarium oxysporum f.sp. niveum on some Curcurbitaceae, Lagenaria, Luffa, Benincasa and commercial rootstocks was evaluated. Effects of grafting on yield and quality of diseased plants were evaluated. All grafted plants and rootstocks were resistant to the three known races (0, 1, and 2) of F. oxysporum f.sp. niveum except watermelon cv. 'Crimson Tide', which was susceptible to race 2. Fruit yield was positively (21-112%) affected by Lagenaria rootstocks but negatively affected (200-267%) by Cucurbita rootstocks when compared with the control. While only minor differences in fruit quality were determined in control and grafted plants on Lagenaria rootstocks, the quality parameters for watermelon grafted onto Cucurbita rootstocks were lower than in the control. The reasons for low yield and quality might be due to an incompatibility between Cucurbita rootstocks and watermelon. These results showed that rootstock influence on disease resistance as well as yield and quality of scion fruit is important in determining the potential use of grafting applications in watermelon. This research was supported by Project No. TOGTAGT ARP-2410 from The Scientific and Technical Research Council of Turkey (TUBITAK),A nkara, Turkey.