PREFACE Dear Colleagues, This book of proceedings contains the full-length contributed papers of ... more PREFACE Dear Colleagues, This book of proceedings contains the full-length contributed papers of the lectures and posters presented at Cucurbitaceae 2016, the XI th Eucarpia Meeting on Cucurbit Genetics and Breeding. The date of issue of this book is July 24, 2016, the first day of the conference, following the cucurbit-meeting tradition initiated at the
The plants of summer squash, Cucurbita pepo , are monoecious, bearing their flowers in leaf axils... more The plants of summer squash, Cucurbita pepo , are monoecious, bearing their flowers in leaf axils. Plants of C. pepo subsp. pepo , which includes Cocozelle and Zucchini squash, bear one flower per leaf axil whilst plants of C. pepo subsp. texana , which includes Crookneck squash, differentiate two or more flower buds at nearly all leaf axils. This multiple-flowering trait, conferred by the single recessive gene mf , was introgressed from a Crookneck squash (subsp. texana ) into several inbreds of Cocozelle and Zucchini squash (subsp. pepo ) through six backcross generations. The nearly isogenic hybrids derived from crossing these inbreds, single- and multiple-flowered, were compared with one another in replicated field trials with the purpose of determining whether or not the multiple-flowering trait can significantly increase yields of Cocozelle and Zucchini under field conditions. The results showed that the multiple-flowering trait can increase yield in Cocozelle squash by as much as 60% and in Zucchini squash by 24%. The differences in yield between the respective multiple- and single-flowered hybrids were based on number of fruits produced. The yield differences were most greatly expressed from the end of the first week through the third week of harvest in the Cocozelle and during the third week of harvest in the Zucchini.
In the first century CE, two Roman agricultural writers, Lucius Junius Moderatus Columella and Ga... more In the first century CE, two Roman agricultural writers, Lucius Junius Moderatus Columella and Gaius Plinius Secundus (Pliny the Elder), referred to proto-greenhouses (specularia) constructed for the Emperor Tiberius (42 BCE–37 CE) presumably adjacent to his palace, the Villa Jovis on the Isle of Capri. Pliny stated in Historia Naturalis (Book 19, 23:64) that the specularia consisted of beds mounted on wheels that were moved into the sun, and on wintry days withdrawn under the cover of frames glazed with transparent stone (lapis specularis) to provide fruits of cucumis. According to Pliny, this was “a delicacy for which the Emperor Tiberius, had a remarkable partiality; in fact there was never a day on which he was not supplied it.” The cucumis fruits described by Columella and Pliny, long mistranslated as cucumbers, Cucumis sativus, were in fact long-fruited melons, Cucumis melo subsp. melo Flexuosus Group. They are known today as vegetable melons, snake melons, and faqqous, and we...
Cucurbita pepo contains a wealth of genetic variability in fruit size, shape, and color. A common... more Cucurbita pepo contains a wealth of genetic variability in fruit size, shape, and color. A common fruit color pattern in C. pepo is striping of the fruits. Stripes occur on the fruit exterior in accordance with the positions of the 10 main subepidermal vein tracts, and can be normal, with darker stripes occurring between and lighter stripes over and adjacent to the vein tracts, or reversed, with lighter stripes occurring between and darker stripes over and adjacent to the vein tracts. Reverse striping has been reported as being independent and at other times dependent on the presence of the dominant allele for dark stem color, D. The objective of this investigation was to determine the relationship, if any, between the two types of reverse striping, dark-stem-dependent and independent. For this purpose, two accessions, which when crossed produced progeny having dark-stem-dependent reverse striping, were crossed with seven nearisogenic tester accessions of known genotype. The results indicated that the two types of reverse striping are conferred by different alleles at the same locus, which is also the same locus at which other alleles confer normal striping. The results of crossing among the nine accessions suggest that two genes reported as having major effects on fruit color, l-2 and W, are actually the same locus (or two tightly linked loci). To minimize possible confusion, it is suggested that this multiple-allelic locus be hereafter referred to as l-2. This locus has seven alleles, of which the two top dominants, L-2 WS and L-2 W , and the bottom recessive, l-2, confer the exact same fruit phenotype, weak coloration. Two intermediate alleles, L-2 and L-2 i , result in intense fruit coloration and normal striping, and two other intermediate alleles, L-2 Wr and l-2 R , respectively, confer dark-stem-dependent and independent reverse striping. The order of dominance of the seven alleles is L-2 WS [ L-2 W [ L-2 Wr [ L-2 [ L-2 i [ l-2 R [ l-2.
Taste has been the subject of human selection in the evolution of agricultural crops, and acidity... more Taste has been the subject of human selection in the evolution of agricultural crops, and acidity is one of the three major components of fleshy fruit taste, together with sugars and volatile flavour compounds. We identify a family of plant-specific genes with a major effect on fruit acidity by map-based cloning of C. melo PH gene (CmPH) from melon, Cucumis melo taking advantage of the novel natural genetic variation for both high and low fruit acidity in this species. Functional silencing of orthologous PH genes in two distantly related plant families, cucumber and tomato, produced low-acid, bland tasting fruit, showing that PH genes control fruit acidity across plant families. A four amino-acid duplication in CmPH distinguishes between primitive acidic varieties and modern dessert melons. This fortuitous mutation served as a preadaptive antecedent to the development of sweet melon cultigens in Central Asia over 1,000 years ago.
Acorn squash (Cucurbita pepo) is a familiar fruit vegetable in North America, appreciated for its... more Acorn squash (Cucurbita pepo) is a familiar fruit vegetable in North America, appreciated for its attractive appearance, good flavor, nutritional content and long storage life. A breeding program in Israel has produced three new acorn squash hybrids of enhanced sweetness and flavor. Presently, we evaluated productivity, quality, and storability of these new cultivars in fall plantings. The plants were grown trellised, in an insect-proof greenhouse, for fruit production during the winter to meet consumer demand. The plants were highly productive and bore fruits of superb quality, but there was a high incidence of fungal rots during postharvest cold storage. Pre-treating the fruits with hot water brushing and rinsing before storage was found effective in reducing rot incidence of the fruits stored at 15 °C, but only for one cultivar. Storing the fruits at 10 °C with reduced humidity (Rh 70%) enabled a 3-month shelf life with significantly reduced fruit-rot incidence and minimal effect...
'Striato d'Italia' (cocozelle group) and 'Clarita' (vegetable marrow group) summer squash were gr... more 'Striato d'Italia' (cocozelle group) and 'Clarita' (vegetable marrow group) summer squash were grown in the greenhouse and field in the presence of sweetpotato whiteflies (Bemisia tabaci Germ.) and their susceptibility to leaf silvering was compared. Silvering was less severe in 'Striato d'Italia' in the greenhouse and field. Leaf silvering is an economically important malady of squash and pumpkins (Cucurbita spp.) that is incited by the sweetpotato whitefly (Schuster et al., 1991; Yokomi et al., 1990) and exacerbated by drought stress (Paris et al., 1987). The three major species of squash and pumpkins-C. pepo L., C. maxima Duch. ex Lam., and C. moschata (Duch. ex Lam.) Duch. ex Poir.-are susceptible, including many C. pepo cultivars that have been affected severely (Burger et al., 1983; Maynard and Cantliffe, 1989; Simons et al., 1989). In Israel, during a season in which only mild to moderate leaf silvering occurred, 'Bareqet' was less affected by silvering than 'Clarita' (both C.pepo) (Edelstein et al., 1991). At the Agricultural Research and Education Center (AREC), Fort Pierce, Fla., some C. pepo cultivars were less affected by silvering than others (unpublished data). The objectives of the present work were to determine whether differential leaf silvering susceptibility occurs in C. pepo and if it is consistent among various growing conditions. Based on observations by Edelstein et al. (1991) and ourselves, two cultivars were chosen for comparison: 'Clarita' (vegetable marrow group, probably highly susceptible) and 'Striato d'Italia' (cocozelle group, probably less susceptible) (Paris, 1986). 'Clarita' seeds were obtained from Petoseed (Saticoy, Calif.).
Zucchini squash (Cucurbita pepo L.) fruit yield and the incidence of sweetpotato whitefly (SPWF) ... more Zucchini squash (Cucurbita pepo L.) fruit yield and the incidence of sweetpotato whitefly (SPWF) [Bemisia tabaci (Gennadius)], squash silver leaf (SSL) disorder, and zucchini yellow mosaic virus (ZYMV) were measured during Spring and Fall 1991 in experiments containing various plant populations. In both experiments, as the within-row spacing increased from 30.5 to 76.2 cm or the number of plants per hill decreased from three to one, the number of marketable fruit per hectare decreased, and the marketable fruit per plant increased. Adult SPWF populations increased with decreased within-row spacing in the spring but not the fall experiment. The incidence of SSL or ZYMV infection was not affected by plant population in either experiment. The results indicate that increasing zucchini squash plant population can increase yield without affecting the incidence of SSL or ZYMV.
The fruits of Cucurbita pepo cv. Table Queen are light green when young, turn dark green by inter... more The fruits of Cucurbita pepo cv. Table Queen are light green when young, turn dark green by intermediate age (15-18 days past anthesis) and remain dark green through maturity. Three major genes are known to affect developmental fruit color intensity in C. pepo: D, 1-1, and 1-2. Table Queen was crossed with cv. Vegetable Spaghetti and with tester stocks of known genotype in order to determine the genetic basis of its developmental fruit coloration. The results from filial, backcross. and testcross generations suggest that Table Queen carries gene D, which confers dark stem and fruit color from intermediate fruit age through maturity. Table Queen also carries L-2. which confers Light Type 2 (a pattern of grayish green hue) fruit color from intermediate age, but D is epistatic to L-2. The genotype of Table Queen is D/D 1-1/1-1 L-2/L-2. Clear-cut results were not obtained -- regarding the genetic basis of the retention of green color through maturity of Table Queen fruits.
Summer squash (Cucurbita pepo L.) plants were grown in pots with high (290% capacity) or low (45%... more Summer squash (Cucurbita pepo L.) plants were grown in pots with high (290% capacity) or low (45% to 70% of capacity) soil moisture. The plants were exposed or not exposed to sweetpotato whiteflies (Bemisia tabaci Genn.). Only the plants exposed to whiteflies developed leaf silvering. Silvering was more severe in plants subjected to low soil moisture.
Most cultivars of acorn squash (Cucurbita pepo), such as `Table Queen', have fruit that are l... more Most cultivars of acorn squash (Cucurbita pepo), such as `Table Queen', have fruit that are light green when young, become dark green by intermediate age, and remain dark green through maturity, carrying genotype D/D l-l/l-1 L-2/L-2. Many other forms of C. pepo that carry this genotype, the most familiar being the Halloween and pie pumpkins, turn orange at maturity. The genetic basis for green color retention of acorn squash was investigated by crossing `Table Queen' with `Vegetable Spaghetti', `Fordhook Zucchini', and accession 85k-9-107-2 (the parental, filial, backcross, and testcross generation progenies being grown out in the field and observed and scored for fruit color at maturity, between 40 and 44 days past anthesis). The results indicated that the three stocks crossed with `Table Queen' carry two recessive genes, designated mature orange-1 (mo-1) and mature orange-2 (mo-2), which act in concert to result in complete loss of green color before maturity i...
Most summer squash, Cucurbita pepo L., produce one flower bud per leaf axil, whereas some genotyp... more Most summer squash, Cucurbita pepo L., produce one flower bud per leaf axil, whereas some genotypes can produce two or more. The former genotypes are referred to as single-flowering, whereas the latter are referred to as multiple-flowering. The objective was to determine the mode of inheritance of multiple flowering. The zucchini ‘True French’, which is single-flowering, was crossed with Accession 1777, a nearly isogenic line of this cultivar, which is multiple-flowering. Parental, filial, and back-cross plants were grown in pots in the greenhouse and each of their first 15 leaf axils was scored for the number of flower buds. Nearly all F1 plants, regardless of the direction of the cross, and plants resulting from back-crossing to ‘True French’ were single-flowering. Approximately one-fourth of the F2 plants, regardless of the direction of the cross, and half of the plants of the back-cross to 1777 produced two flowers at one or more leaf axils. These results indicate that the abili...
Pumpkin and squash (Cucurbita L. spp.) are important cucurbit crops and are grown in almost all a... more Pumpkin and squash (Cucurbita L. spp.) are important cucurbit crops and are grown in almost all arable regions of the world. The three economically important species, Cucurbita pepo L., Cucurbita moschata Duchesne, and Cucurbita maxima Duchesne are highly polymorphic in fruit characteristics, inspiring much research into their inheritance. A comprehensive list of genes for Cucurbita was last published more than a decade ago. This new gene list for pumpkin and squash includes descriptions of gene interactions and the genetic background of the parents that had been used for crossing to allow easy confirmation of previous work and provide a sound foundation for further investigation. This gene list includes 79 loci for phenotypic/morphological traits and 48 polymorphic allozyme loci. Linkage and mapping are discussed.
Journal of the American Society for Horticultural Science
Fruit sweetness is the major determinant of fruit quality in melons (Cucumis melo L.) and reflect... more Fruit sweetness is the major determinant of fruit quality in melons (Cucumis melo L.) and reflects the concentration of the three major soluble sugars, sucrose, glucose, and fructose, present in the fruit flesh. Of these three sugars, sucrose is the prime factor accounting for both the genetic and the environmental variability observed in sugar content of C. melo fruit. Faqqous (subsp. melo var. flexuosus), a cultivar having a low sucrose and total sugar content, was crossed with Noy Yizre'el (subsp. melo var. reticulatus), a cultivar having a high sucrose and total sugar content. F1 plants had a sucrose content averaging slightly higher than that of the low-sucrose parent, indicating that low sucrose content is nearly completely dominant. Segregation in the F2 and backcross progenies indicated that high sucrose accumulation in melon fruit flesh is conferred by a single recessive gene herein designated suc. When the high-sucrose parent was crossed with the moderate-sucrose landr...
Summer squash (Cucurbita pepo L.) is grown in many temperate and subtropical regions, ranking hig... more Summer squash (Cucurbita pepo L.) is grown in many temperate and subtropical regions, ranking high in economic importance among vegetable crops worldwide. A native of North America, summer squash has been grown in Europe since the Renaissance. There are six extant horticultural groups of summer squash: cocozelle, crookneck, scallop, straightneck, vegetable marrow, and zucchini. Most of these groups have existed for hundreds of years. Their differing fruit shapes result in their differential adaptations to various methods of culinary preparation. Differences in flavor, while often subtle, are readily apparent in some instances. The groups differ in geographical distribution and economic importance. The zucchini group, a relatively recent development, has undergone intensive breeding in the United States and Europe and is probably by far the most widely grown and economically important of the summer squash.
PREFACE Dear Colleagues, This book of proceedings contains the full-length contributed papers of ... more PREFACE Dear Colleagues, This book of proceedings contains the full-length contributed papers of the lectures and posters presented at Cucurbitaceae 2016, the XI th Eucarpia Meeting on Cucurbit Genetics and Breeding. The date of issue of this book is July 24, 2016, the first day of the conference, following the cucurbit-meeting tradition initiated at the
The plants of summer squash, Cucurbita pepo , are monoecious, bearing their flowers in leaf axils... more The plants of summer squash, Cucurbita pepo , are monoecious, bearing their flowers in leaf axils. Plants of C. pepo subsp. pepo , which includes Cocozelle and Zucchini squash, bear one flower per leaf axil whilst plants of C. pepo subsp. texana , which includes Crookneck squash, differentiate two or more flower buds at nearly all leaf axils. This multiple-flowering trait, conferred by the single recessive gene mf , was introgressed from a Crookneck squash (subsp. texana ) into several inbreds of Cocozelle and Zucchini squash (subsp. pepo ) through six backcross generations. The nearly isogenic hybrids derived from crossing these inbreds, single- and multiple-flowered, were compared with one another in replicated field trials with the purpose of determining whether or not the multiple-flowering trait can significantly increase yields of Cocozelle and Zucchini under field conditions. The results showed that the multiple-flowering trait can increase yield in Cocozelle squash by as much as 60% and in Zucchini squash by 24%. The differences in yield between the respective multiple- and single-flowered hybrids were based on number of fruits produced. The yield differences were most greatly expressed from the end of the first week through the third week of harvest in the Cocozelle and during the third week of harvest in the Zucchini.
In the first century CE, two Roman agricultural writers, Lucius Junius Moderatus Columella and Ga... more In the first century CE, two Roman agricultural writers, Lucius Junius Moderatus Columella and Gaius Plinius Secundus (Pliny the Elder), referred to proto-greenhouses (specularia) constructed for the Emperor Tiberius (42 BCE–37 CE) presumably adjacent to his palace, the Villa Jovis on the Isle of Capri. Pliny stated in Historia Naturalis (Book 19, 23:64) that the specularia consisted of beds mounted on wheels that were moved into the sun, and on wintry days withdrawn under the cover of frames glazed with transparent stone (lapis specularis) to provide fruits of cucumis. According to Pliny, this was “a delicacy for which the Emperor Tiberius, had a remarkable partiality; in fact there was never a day on which he was not supplied it.” The cucumis fruits described by Columella and Pliny, long mistranslated as cucumbers, Cucumis sativus, were in fact long-fruited melons, Cucumis melo subsp. melo Flexuosus Group. They are known today as vegetable melons, snake melons, and faqqous, and we...
Cucurbita pepo contains a wealth of genetic variability in fruit size, shape, and color. A common... more Cucurbita pepo contains a wealth of genetic variability in fruit size, shape, and color. A common fruit color pattern in C. pepo is striping of the fruits. Stripes occur on the fruit exterior in accordance with the positions of the 10 main subepidermal vein tracts, and can be normal, with darker stripes occurring between and lighter stripes over and adjacent to the vein tracts, or reversed, with lighter stripes occurring between and darker stripes over and adjacent to the vein tracts. Reverse striping has been reported as being independent and at other times dependent on the presence of the dominant allele for dark stem color, D. The objective of this investigation was to determine the relationship, if any, between the two types of reverse striping, dark-stem-dependent and independent. For this purpose, two accessions, which when crossed produced progeny having dark-stem-dependent reverse striping, were crossed with seven nearisogenic tester accessions of known genotype. The results indicated that the two types of reverse striping are conferred by different alleles at the same locus, which is also the same locus at which other alleles confer normal striping. The results of crossing among the nine accessions suggest that two genes reported as having major effects on fruit color, l-2 and W, are actually the same locus (or two tightly linked loci). To minimize possible confusion, it is suggested that this multiple-allelic locus be hereafter referred to as l-2. This locus has seven alleles, of which the two top dominants, L-2 WS and L-2 W , and the bottom recessive, l-2, confer the exact same fruit phenotype, weak coloration. Two intermediate alleles, L-2 and L-2 i , result in intense fruit coloration and normal striping, and two other intermediate alleles, L-2 Wr and l-2 R , respectively, confer dark-stem-dependent and independent reverse striping. The order of dominance of the seven alleles is L-2 WS [ L-2 W [ L-2 Wr [ L-2 [ L-2 i [ l-2 R [ l-2.
Taste has been the subject of human selection in the evolution of agricultural crops, and acidity... more Taste has been the subject of human selection in the evolution of agricultural crops, and acidity is one of the three major components of fleshy fruit taste, together with sugars and volatile flavour compounds. We identify a family of plant-specific genes with a major effect on fruit acidity by map-based cloning of C. melo PH gene (CmPH) from melon, Cucumis melo taking advantage of the novel natural genetic variation for both high and low fruit acidity in this species. Functional silencing of orthologous PH genes in two distantly related plant families, cucumber and tomato, produced low-acid, bland tasting fruit, showing that PH genes control fruit acidity across plant families. A four amino-acid duplication in CmPH distinguishes between primitive acidic varieties and modern dessert melons. This fortuitous mutation served as a preadaptive antecedent to the development of sweet melon cultigens in Central Asia over 1,000 years ago.
Acorn squash (Cucurbita pepo) is a familiar fruit vegetable in North America, appreciated for its... more Acorn squash (Cucurbita pepo) is a familiar fruit vegetable in North America, appreciated for its attractive appearance, good flavor, nutritional content and long storage life. A breeding program in Israel has produced three new acorn squash hybrids of enhanced sweetness and flavor. Presently, we evaluated productivity, quality, and storability of these new cultivars in fall plantings. The plants were grown trellised, in an insect-proof greenhouse, for fruit production during the winter to meet consumer demand. The plants were highly productive and bore fruits of superb quality, but there was a high incidence of fungal rots during postharvest cold storage. Pre-treating the fruits with hot water brushing and rinsing before storage was found effective in reducing rot incidence of the fruits stored at 15 °C, but only for one cultivar. Storing the fruits at 10 °C with reduced humidity (Rh 70%) enabled a 3-month shelf life with significantly reduced fruit-rot incidence and minimal effect...
'Striato d'Italia' (cocozelle group) and 'Clarita' (vegetable marrow group) summer squash were gr... more 'Striato d'Italia' (cocozelle group) and 'Clarita' (vegetable marrow group) summer squash were grown in the greenhouse and field in the presence of sweetpotato whiteflies (Bemisia tabaci Germ.) and their susceptibility to leaf silvering was compared. Silvering was less severe in 'Striato d'Italia' in the greenhouse and field. Leaf silvering is an economically important malady of squash and pumpkins (Cucurbita spp.) that is incited by the sweetpotato whitefly (Schuster et al., 1991; Yokomi et al., 1990) and exacerbated by drought stress (Paris et al., 1987). The three major species of squash and pumpkins-C. pepo L., C. maxima Duch. ex Lam., and C. moschata (Duch. ex Lam.) Duch. ex Poir.-are susceptible, including many C. pepo cultivars that have been affected severely (Burger et al., 1983; Maynard and Cantliffe, 1989; Simons et al., 1989). In Israel, during a season in which only mild to moderate leaf silvering occurred, 'Bareqet' was less affected by silvering than 'Clarita' (both C.pepo) (Edelstein et al., 1991). At the Agricultural Research and Education Center (AREC), Fort Pierce, Fla., some C. pepo cultivars were less affected by silvering than others (unpublished data). The objectives of the present work were to determine whether differential leaf silvering susceptibility occurs in C. pepo and if it is consistent among various growing conditions. Based on observations by Edelstein et al. (1991) and ourselves, two cultivars were chosen for comparison: 'Clarita' (vegetable marrow group, probably highly susceptible) and 'Striato d'Italia' (cocozelle group, probably less susceptible) (Paris, 1986). 'Clarita' seeds were obtained from Petoseed (Saticoy, Calif.).
Zucchini squash (Cucurbita pepo L.) fruit yield and the incidence of sweetpotato whitefly (SPWF) ... more Zucchini squash (Cucurbita pepo L.) fruit yield and the incidence of sweetpotato whitefly (SPWF) [Bemisia tabaci (Gennadius)], squash silver leaf (SSL) disorder, and zucchini yellow mosaic virus (ZYMV) were measured during Spring and Fall 1991 in experiments containing various plant populations. In both experiments, as the within-row spacing increased from 30.5 to 76.2 cm or the number of plants per hill decreased from three to one, the number of marketable fruit per hectare decreased, and the marketable fruit per plant increased. Adult SPWF populations increased with decreased within-row spacing in the spring but not the fall experiment. The incidence of SSL or ZYMV infection was not affected by plant population in either experiment. The results indicate that increasing zucchini squash plant population can increase yield without affecting the incidence of SSL or ZYMV.
The fruits of Cucurbita pepo cv. Table Queen are light green when young, turn dark green by inter... more The fruits of Cucurbita pepo cv. Table Queen are light green when young, turn dark green by intermediate age (15-18 days past anthesis) and remain dark green through maturity. Three major genes are known to affect developmental fruit color intensity in C. pepo: D, 1-1, and 1-2. Table Queen was crossed with cv. Vegetable Spaghetti and with tester stocks of known genotype in order to determine the genetic basis of its developmental fruit coloration. The results from filial, backcross. and testcross generations suggest that Table Queen carries gene D, which confers dark stem and fruit color from intermediate fruit age through maturity. Table Queen also carries L-2. which confers Light Type 2 (a pattern of grayish green hue) fruit color from intermediate age, but D is epistatic to L-2. The genotype of Table Queen is D/D 1-1/1-1 L-2/L-2. Clear-cut results were not obtained -- regarding the genetic basis of the retention of green color through maturity of Table Queen fruits.
Summer squash (Cucurbita pepo L.) plants were grown in pots with high (290% capacity) or low (45%... more Summer squash (Cucurbita pepo L.) plants were grown in pots with high (290% capacity) or low (45% to 70% of capacity) soil moisture. The plants were exposed or not exposed to sweetpotato whiteflies (Bemisia tabaci Genn.). Only the plants exposed to whiteflies developed leaf silvering. Silvering was more severe in plants subjected to low soil moisture.
Most cultivars of acorn squash (Cucurbita pepo), such as `Table Queen', have fruit that are l... more Most cultivars of acorn squash (Cucurbita pepo), such as `Table Queen', have fruit that are light green when young, become dark green by intermediate age, and remain dark green through maturity, carrying genotype D/D l-l/l-1 L-2/L-2. Many other forms of C. pepo that carry this genotype, the most familiar being the Halloween and pie pumpkins, turn orange at maturity. The genetic basis for green color retention of acorn squash was investigated by crossing `Table Queen' with `Vegetable Spaghetti', `Fordhook Zucchini', and accession 85k-9-107-2 (the parental, filial, backcross, and testcross generation progenies being grown out in the field and observed and scored for fruit color at maturity, between 40 and 44 days past anthesis). The results indicated that the three stocks crossed with `Table Queen' carry two recessive genes, designated mature orange-1 (mo-1) and mature orange-2 (mo-2), which act in concert to result in complete loss of green color before maturity i...
Most summer squash, Cucurbita pepo L., produce one flower bud per leaf axil, whereas some genotyp... more Most summer squash, Cucurbita pepo L., produce one flower bud per leaf axil, whereas some genotypes can produce two or more. The former genotypes are referred to as single-flowering, whereas the latter are referred to as multiple-flowering. The objective was to determine the mode of inheritance of multiple flowering. The zucchini ‘True French’, which is single-flowering, was crossed with Accession 1777, a nearly isogenic line of this cultivar, which is multiple-flowering. Parental, filial, and back-cross plants were grown in pots in the greenhouse and each of their first 15 leaf axils was scored for the number of flower buds. Nearly all F1 plants, regardless of the direction of the cross, and plants resulting from back-crossing to ‘True French’ were single-flowering. Approximately one-fourth of the F2 plants, regardless of the direction of the cross, and half of the plants of the back-cross to 1777 produced two flowers at one or more leaf axils. These results indicate that the abili...
Pumpkin and squash (Cucurbita L. spp.) are important cucurbit crops and are grown in almost all a... more Pumpkin and squash (Cucurbita L. spp.) are important cucurbit crops and are grown in almost all arable regions of the world. The three economically important species, Cucurbita pepo L., Cucurbita moschata Duchesne, and Cucurbita maxima Duchesne are highly polymorphic in fruit characteristics, inspiring much research into their inheritance. A comprehensive list of genes for Cucurbita was last published more than a decade ago. This new gene list for pumpkin and squash includes descriptions of gene interactions and the genetic background of the parents that had been used for crossing to allow easy confirmation of previous work and provide a sound foundation for further investigation. This gene list includes 79 loci for phenotypic/morphological traits and 48 polymorphic allozyme loci. Linkage and mapping are discussed.
Journal of the American Society for Horticultural Science
Fruit sweetness is the major determinant of fruit quality in melons (Cucumis melo L.) and reflect... more Fruit sweetness is the major determinant of fruit quality in melons (Cucumis melo L.) and reflects the concentration of the three major soluble sugars, sucrose, glucose, and fructose, present in the fruit flesh. Of these three sugars, sucrose is the prime factor accounting for both the genetic and the environmental variability observed in sugar content of C. melo fruit. Faqqous (subsp. melo var. flexuosus), a cultivar having a low sucrose and total sugar content, was crossed with Noy Yizre'el (subsp. melo var. reticulatus), a cultivar having a high sucrose and total sugar content. F1 plants had a sucrose content averaging slightly higher than that of the low-sucrose parent, indicating that low sucrose content is nearly completely dominant. Segregation in the F2 and backcross progenies indicated that high sucrose accumulation in melon fruit flesh is conferred by a single recessive gene herein designated suc. When the high-sucrose parent was crossed with the moderate-sucrose landr...
Summer squash (Cucurbita pepo L.) is grown in many temperate and subtropical regions, ranking hig... more Summer squash (Cucurbita pepo L.) is grown in many temperate and subtropical regions, ranking high in economic importance among vegetable crops worldwide. A native of North America, summer squash has been grown in Europe since the Renaissance. There are six extant horticultural groups of summer squash: cocozelle, crookneck, scallop, straightneck, vegetable marrow, and zucchini. Most of these groups have existed for hundreds of years. Their differing fruit shapes result in their differential adaptations to various methods of culinary preparation. Differences in flavor, while often subtle, are readily apparent in some instances. The groups differ in geographical distribution and economic importance. The zucchini group, a relatively recent development, has undergone intensive breeding in the United States and Europe and is probably by far the most widely grown and economically important of the summer squash.
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