Hiroko Takagi - Academia.edu (original) (raw)
Papers by Hiroko Takagi
Sweet potato, Jpomoea batatas (L.) Lam., plays a very important role in traditional cropping syst... more Sweet potato, Jpomoea batatas (L.) Lam., plays a very important role in traditional cropping systems in the tropics and sub-tropics. It ranks fifth among food crops in terms of total production in developing countries. Despite its importance and the large number of germplasm accessions collected, useful genetic markers in sweet potato and its wild relatives are quite limited in comparison with many other crop plants die to bilogical characteristics such as polyploidy, vegetative propagation, self and cross-incompatibility. In this paper, past and present status of collection and evaluation of sweet potato germplasm is outlined. Problems and needs for the further development of the germplasm activities are also discussed.
BMC biology, Jan 19, 2017
Root and tuber crops are a major food source in tropical Africa. Among these crops are several sp... more Root and tuber crops are a major food source in tropical Africa. Among these crops are several species in the monocotyledonous genus Dioscorea collectively known as yam, a staple tuber crop that contributes enormously to the subsistence and socio-cultural lives of millions of people, principally in West and Central Africa. Yam cultivation is constrained by several factors, and yam can be considered a neglected "orphan" crop that would benefit from crop improvement efforts. However, the lack of genetic and genomic tools has impeded the improvement of this staple crop. To accelerate marker-assisted breeding of yam, we performed genome analysis of white Guinea yam (Dioscorea rotundata) and assembled a 594-Mb genome, 76.4% of which was distributed among 21 linkage groups. In total, we predicted 26,198 genes. Phylogenetic analyses with 2381 conserved genes revealed that Dioscorea is a unique lineage of monocotyledons distinct from the Poales (rice), Arecales (palm), and Zingibe...
Plos One, 2019
Dioecy (distinct male and female individuals) and scarce to non-flowering are common features of ... more Dioecy (distinct male and female individuals) and scarce to non-flowering are common features of cultivated yam (Dioscorea spp.). However, the molecular mechanisms underlying flowering and sex determination in Dioscorea are largely unknown. We conducted Super-SAGE transcriptome profiling of male, female and monoecious individuals to identify flowering and sex-related genes in white Guinea yam (D. rotundata), generating 20,236 unique tags. Of these, 13,901 were represented by a minimum of 10 tags. A total 88 tags were significantly differentially expressed in male, female and monoecious plants, of which 18 corresponded to genes previously implicated in flower development and sex determination in multiple plant species. We validated the SuperSAGE data with quantitative real-time PCR (qRT-PCR)-based analysis of the expression of three candidate genes. We further investigated the flowering patterns of 1938 D. rotundata accessions representing diverse geographical origins over two consecutive years. Over 85% of accessions were either male or non-flowering, less than 15% were female, while monoecious plants were rare. Intensity of flowering varied between male and female plants, with the former flowering more abundantly than the latter. Candidate genes identified in this study can be targeted for further validation and to induce regular flowering in poor to non-flowering culti-vars. Findings of the study provide important inputs for further studies aiming to overcome the challenge of flowering in yams and to improve efficiency of yam breeding.
Proceedings of the National Academy of Sciences
White Guinea yam (Dioscorea rotundata) is an important staple tuber crop in West Africa. However,... more White Guinea yam (Dioscorea rotundata) is an important staple tuber crop in West Africa. However, its origin remains unclear. In this study, we resequenced 336 accessions of white Guinea yam and compared them with the sequences of wild Dioscorea species using an improved reference genome sequence of D. rotundata. In contrast to a previous study suggesting that D. rotundata originated from a subgroup of Dioscorea praehensilis, our results suggest a hybrid origin of white Guinea yam from crosses between the wild rainforest species D. praehensilis and the savannah-adapted species Dioscorea abyssinica. We identified a greater genomic contribution from D. abyssinica in the sex chromosome of Guinea yam and extensive introgression around the SWEETIE gene. Our findings point to a complex domestication scenario for Guinea yam and highlight the importance of wild species as gene donors for improving this crop through molecular breeding.
Dioecy (distinct male and female individuals) combined with scarce to non-flowering are common fe... more Dioecy (distinct male and female individuals) combined with scarce to non-flowering are common features of cultivated yam (Dioscorea spp.). However, the molecular mechanisms underlying flowering and sex determination in Dioscorea are unknown. We conducted SuperSAGE transcriptome profiling of male, female and monoecious individuals to identify flowering and sex-related genes in white Guinea yam (D. rotundata). SuperSAGE analysis generated a total of 20,236 unique tags, of which 13,901 were represented by a minimum of 10 tags. Of these, 88 tags were significantly differentially expressed in male, female and monoecious plants. Of the 88 differentially expressed SuperSAGE tags, 18 corresponded to genes previously implicated in flower development and sex determination in multiple plant species. We validated the SuperSAGE data with quantitative real-time PCR (qRT-PCR)-based analysis of the expression of four candidate genes. Our findings suggest that mechanisms of flowering and sex determ...
Scientific Reports
In sugarcane (Saccharum spp. hybrid) breeding, introgression of useful genes via intergeneric hyb... more In sugarcane (Saccharum spp. hybrid) breeding, introgression of useful genes via intergeneric hybridization is a powerful strategy for improving the crop productivity. Erianthus arundinaceus shows great potential in terms of useful traits; however, little is known about the cytogenetic and agronomic characteristics of intergeneric hybrids between these two species. Here, we examine the cytogenetic and agronomic characteristics, and relationships between the two in intergeneric F 1 hybrids between modern sugarcane cultivar and E. arundinaceus identified by amplification of 5S rDNA markers and morphological characteristics. The nuclear DNA content of the hybrids varied from 6.07 to 8.94 pg/2C, with intra-clonal variation in DNA content and 5S rDNA sites. Genomic in situ hybridization revealed 53 to 82 chromosomes in the hybrids, with 53 to 56 derived from sugarcane and 1 to 29 from E. arundinaceus. There were significant positive correlations between the number of E. arundinaceus chromosomes and dry matter yield, millable stalk weight, single stalk weight, and stalk diameter, but not sucrose content, reducing sugar content, sucrose/reducing sugar ratio or fiber content. This detailed information on intergeneric F 1 hybrids between modern sugarcane cultivar and E. arundinaceus will contribute to effective utilization of E. arundinaceus in sugarcane breeding. Sugarcane is an economically important crop with worldwide production of 1.9 billion tons 1 , accounting for two-thirds of the world's sugar production and providing feedstocks for bio-energy production. Further improvement of this crop's productivity will contribute to promoting food sustainability and energy security. Highly polyploid (2n = 100-130) modern sugarcane cultivars (Saccharum spp. hybrid) were derived via complex interspecific crosses between the sugar-producing species S. officinarum (2n = 10x = 80) and the wild species S. spontaneum (2n = 40-128). This interspecific hybridization, which was first performed a century ago, plays a major role in improving yield, disease resistance, and adaptability to abiotic stresses in sugarcane cultivars. However, only a limited number of parental materials have contributed to this interspecific hybridization, resulting in a narrow genetic base and limiting the scope for further improvements in sugarcane production 2,3. To broaden the genetic base of modern sugarcane cultivars, breeders have expanded their interest to intergeneric hybridization utilizing sugarcane-related genera belonging to the so-called 'Saccharum complex' , which includes Erianthus, Miscanthus, Sclerostachya, and Narenga 4. Of these, Erianthus arundinaceus (Rez.) Jeswiet shows considerable potential as breeding material due the high biomass productivity, superior ratoon ability, and exceptional adaptability to biotic and abiotic stresses of resulting sugarcane cultivars 5. Despite the importance of the Erianthus germplasm in sugarcane breeding, the large genetic distance between Saccharum and Erianthus results in cross-incompatibility 6-8 , a major constraint in generating intergeneric hybrids. Further constraints arise from the difficulty of distinguishing between genuine intergeneric hybrids and
Cowpea is an important protein primary source in West Africa. To improve both productivity and gr... more Cowpea is an important protein primary source in West Africa. To improve both productivity and grain quality, a rapid, precise, robust, and cost-effective method of estimating the grain nitrogen content of samples grown under various conditions is needed for agronomic and breeding studies. Here, the researchers aimed to 1) develop robust calibration models to predict grain nitrogen content by near-infrared and mid-infrared spectroscopy; and 2) to evaluate the models' adaptability by testing variable samples of cowpea grown in three different agro-ecological zones of West Africa. A total of 251 germplasm accessions with wide variation in grain nitrogen content (2.97% to 5.04%) were used for calibration model development. The new models were validated by using 27 genotypes grown in three locations. The calibration model using both near-infrared and mid-infrared spectroscopy had reasonable accuracy (R 2 = 0.90, RMSECV = 0.07) in cross-validation, and it predicted the nitrogen conte...
Plant Genetic Resources, 2015
Cowpea is traditionally important as an affordable source of protein and minerals and of cash inc... more Cowpea is traditionally important as an affordable source of protein and minerals and of cash income in sub-Saharan Africa, especially for small-scale farmers who have limited options for food and cash crops. The development and deployment of cowpea varieties with improved nutrition and quality that meet the needs of farmers and consumers should enhance cowpea consumption and production in the region. We have identified genetic diversity in various grain quality-related traits of cowpea and relationships among the traits. Wide genetic variation and strong correlations among crude protein, Fe and Zn contents suggest the possibility of improving the concentrations of these nutritional factors simultaneously. Low associations among physical and nutritional properties of grain indicate the possibility of introgressing favorable traits utilizing identified genetic resources. However, narrow variation in amino acid (AA) composition suggests a lesser possibility of improving the contents o...
Biotechnology in Agriculture and Forestry, 2002
Breeding Science, 2006
In order to develop an efficient method of shuttle breeding with rapid generation advancement app... more In order to develop an efficient method of shuttle breeding with rapid generation advancement applicable to the breeding programme of early maturity wheat in the central to southwestern regions of Japan, the possibility of eliminating late heading plants was investigated by combining fall-sown cultivation on Ishigaki Island (24°N), Okinawa, with spring-sown cultivation at Memuro (42°N), Hokkaido. The analysis of heading traits using wheat cultivars and F 2 populations indicated that the earliness of heading in Okinawa and Hokkaido was closely related to both Ppd and Vrn genotypes and the Vrn genotype, respectively. The two hybrid populations segregating for the Ppd or Vrn genes were subjected to rapid generation advancement (F 2 : Okinawa, F 3 : Hokkaido). The analysis of their photoperiod and vernalization responses showed that the plants with photoperiod sensitivity and winter growth habit were eliminated in Okinawa and those with winter growth habit in Hokkaido. The elimination of photoperiod-sensitive plants significantly decreased the proportion of late heading plants in the F 4 population cultivated in the southwestern region of Japan, whereas it was not influenced by the elimination of the winter type plants. It was confirmed that the earliness of heading in the southwestern region of Japan was closely related to the Ppd genotype and was independent of the Vrn genotype, and also indicated that this system of rapid generation advancement was effective in eliminating the late heading plants with photoperiod sensitivity.
Breeding Science, 2005
Genetic analysis of vernalization and photoperiod responses was carried out using eight wheat cul... more Genetic analysis of vernalization and photoperiod responses was carried out using eight wheat cultivars, in order to investigate the relationship between their genotype and the earliness of heading in the southwestern part of Japan. Allelism test of the genes for the vernalization response showed that three wheat cultivars, 'Fukuwasekomugi', 'Zenkoujikomugi' and 'Schomburgk', harboured Vrn-D1, Vrn-D1 and Vrn-A1, respectively. Among the eight cultivars tested, 'Haruhikari' was sensitive to short photoperiod, while the others were insensitive. Segregation analysis of the photoperiod response in the F 2 and B 1 F 1 populations showed that the very late heading cultivar 'Haruhikari' did not harbour major genes for insensitivity to photoperiod. Six cultivars characterized by medium to late heading, 'Norin 61', 'Zenkoujikomugi', 'Saitama 27', 'Schomburgk', 'Norin 59' and 'Norin 67', carried a single gene for insensitivity, Ppd-S, in common. The extremely early heading cultivar 'Fukuwasekomugi' was found to carry two genes for insensitivity, Ppd-S and Ppd-F, the latter displaying a stronger effect for insensitivity to photoperiod. The present study revealed that the earliness of heading in the southwestern part of Japan was closely related to the Ppd genotype of wheat cultivars, whereas it was independent of the Vrn genotype.
BMC biology, Jan 19, 2017
Root and tuber crops are a major food source in tropical Africa. Among these crops are several sp... more Root and tuber crops are a major food source in tropical Africa. Among these crops are several species in the monocotyledonous genus Dioscorea collectively known as yam, a staple tuber crop that contributes enormously to the subsistence and socio-cultural lives of millions of people, principally in West and Central Africa. Yam cultivation is constrained by several factors, and yam can be considered a neglected "orphan" crop that would benefit from crop improvement efforts. However, the lack of genetic and genomic tools has impeded the improvement of this staple crop. To accelerate marker-assisted breeding of yam, we performed genome analysis of white Guinea yam (Dioscorea rotundata) and assembled a 594-Mb genome, 76.4% of which was distributed among 21 linkage groups. In total, we predicted 26,198 genes. Phylogenetic analyses with 2381 conserved genes revealed that Dioscorea is a unique lineage of monocotyledons distinct from the Poales (rice), Arecales (palm), and Zingibe...
Sweet potato, Jpomoea batatas (L.) Lam., plays a very important role in traditional cropping syst... more Sweet potato, Jpomoea batatas (L.) Lam., plays a very important role in traditional cropping systems in the tropics and sub-tropics. It ranks fifth among food crops in terms of total production in developing countries. Despite its importance and the large number of germplasm accessions collected, useful genetic markers in sweet potato and its wild relatives are quite limited in comparison with many other crop plants die to bilogical characteristics such as polyploidy, vegetative propagation, self and cross-incompatibility. In this paper, past and present status of collection and evaluation of sweet potato germplasm is outlined. Problems and needs for the further development of the germplasm activities are also discussed.
BMC biology, Jan 19, 2017
Root and tuber crops are a major food source in tropical Africa. Among these crops are several sp... more Root and tuber crops are a major food source in tropical Africa. Among these crops are several species in the monocotyledonous genus Dioscorea collectively known as yam, a staple tuber crop that contributes enormously to the subsistence and socio-cultural lives of millions of people, principally in West and Central Africa. Yam cultivation is constrained by several factors, and yam can be considered a neglected "orphan" crop that would benefit from crop improvement efforts. However, the lack of genetic and genomic tools has impeded the improvement of this staple crop. To accelerate marker-assisted breeding of yam, we performed genome analysis of white Guinea yam (Dioscorea rotundata) and assembled a 594-Mb genome, 76.4% of which was distributed among 21 linkage groups. In total, we predicted 26,198 genes. Phylogenetic analyses with 2381 conserved genes revealed that Dioscorea is a unique lineage of monocotyledons distinct from the Poales (rice), Arecales (palm), and Zingibe...
Plos One, 2019
Dioecy (distinct male and female individuals) and scarce to non-flowering are common features of ... more Dioecy (distinct male and female individuals) and scarce to non-flowering are common features of cultivated yam (Dioscorea spp.). However, the molecular mechanisms underlying flowering and sex determination in Dioscorea are largely unknown. We conducted Super-SAGE transcriptome profiling of male, female and monoecious individuals to identify flowering and sex-related genes in white Guinea yam (D. rotundata), generating 20,236 unique tags. Of these, 13,901 were represented by a minimum of 10 tags. A total 88 tags were significantly differentially expressed in male, female and monoecious plants, of which 18 corresponded to genes previously implicated in flower development and sex determination in multiple plant species. We validated the SuperSAGE data with quantitative real-time PCR (qRT-PCR)-based analysis of the expression of three candidate genes. We further investigated the flowering patterns of 1938 D. rotundata accessions representing diverse geographical origins over two consecutive years. Over 85% of accessions were either male or non-flowering, less than 15% were female, while monoecious plants were rare. Intensity of flowering varied between male and female plants, with the former flowering more abundantly than the latter. Candidate genes identified in this study can be targeted for further validation and to induce regular flowering in poor to non-flowering culti-vars. Findings of the study provide important inputs for further studies aiming to overcome the challenge of flowering in yams and to improve efficiency of yam breeding.
Proceedings of the National Academy of Sciences
White Guinea yam (Dioscorea rotundata) is an important staple tuber crop in West Africa. However,... more White Guinea yam (Dioscorea rotundata) is an important staple tuber crop in West Africa. However, its origin remains unclear. In this study, we resequenced 336 accessions of white Guinea yam and compared them with the sequences of wild Dioscorea species using an improved reference genome sequence of D. rotundata. In contrast to a previous study suggesting that D. rotundata originated from a subgroup of Dioscorea praehensilis, our results suggest a hybrid origin of white Guinea yam from crosses between the wild rainforest species D. praehensilis and the savannah-adapted species Dioscorea abyssinica. We identified a greater genomic contribution from D. abyssinica in the sex chromosome of Guinea yam and extensive introgression around the SWEETIE gene. Our findings point to a complex domestication scenario for Guinea yam and highlight the importance of wild species as gene donors for improving this crop through molecular breeding.
Dioecy (distinct male and female individuals) combined with scarce to non-flowering are common fe... more Dioecy (distinct male and female individuals) combined with scarce to non-flowering are common features of cultivated yam (Dioscorea spp.). However, the molecular mechanisms underlying flowering and sex determination in Dioscorea are unknown. We conducted SuperSAGE transcriptome profiling of male, female and monoecious individuals to identify flowering and sex-related genes in white Guinea yam (D. rotundata). SuperSAGE analysis generated a total of 20,236 unique tags, of which 13,901 were represented by a minimum of 10 tags. Of these, 88 tags were significantly differentially expressed in male, female and monoecious plants. Of the 88 differentially expressed SuperSAGE tags, 18 corresponded to genes previously implicated in flower development and sex determination in multiple plant species. We validated the SuperSAGE data with quantitative real-time PCR (qRT-PCR)-based analysis of the expression of four candidate genes. Our findings suggest that mechanisms of flowering and sex determ...
Scientific Reports
In sugarcane (Saccharum spp. hybrid) breeding, introgression of useful genes via intergeneric hyb... more In sugarcane (Saccharum spp. hybrid) breeding, introgression of useful genes via intergeneric hybridization is a powerful strategy for improving the crop productivity. Erianthus arundinaceus shows great potential in terms of useful traits; however, little is known about the cytogenetic and agronomic characteristics of intergeneric hybrids between these two species. Here, we examine the cytogenetic and agronomic characteristics, and relationships between the two in intergeneric F 1 hybrids between modern sugarcane cultivar and E. arundinaceus identified by amplification of 5S rDNA markers and morphological characteristics. The nuclear DNA content of the hybrids varied from 6.07 to 8.94 pg/2C, with intra-clonal variation in DNA content and 5S rDNA sites. Genomic in situ hybridization revealed 53 to 82 chromosomes in the hybrids, with 53 to 56 derived from sugarcane and 1 to 29 from E. arundinaceus. There were significant positive correlations between the number of E. arundinaceus chromosomes and dry matter yield, millable stalk weight, single stalk weight, and stalk diameter, but not sucrose content, reducing sugar content, sucrose/reducing sugar ratio or fiber content. This detailed information on intergeneric F 1 hybrids between modern sugarcane cultivar and E. arundinaceus will contribute to effective utilization of E. arundinaceus in sugarcane breeding. Sugarcane is an economically important crop with worldwide production of 1.9 billion tons 1 , accounting for two-thirds of the world's sugar production and providing feedstocks for bio-energy production. Further improvement of this crop's productivity will contribute to promoting food sustainability and energy security. Highly polyploid (2n = 100-130) modern sugarcane cultivars (Saccharum spp. hybrid) were derived via complex interspecific crosses between the sugar-producing species S. officinarum (2n = 10x = 80) and the wild species S. spontaneum (2n = 40-128). This interspecific hybridization, which was first performed a century ago, plays a major role in improving yield, disease resistance, and adaptability to abiotic stresses in sugarcane cultivars. However, only a limited number of parental materials have contributed to this interspecific hybridization, resulting in a narrow genetic base and limiting the scope for further improvements in sugarcane production 2,3. To broaden the genetic base of modern sugarcane cultivars, breeders have expanded their interest to intergeneric hybridization utilizing sugarcane-related genera belonging to the so-called 'Saccharum complex' , which includes Erianthus, Miscanthus, Sclerostachya, and Narenga 4. Of these, Erianthus arundinaceus (Rez.) Jeswiet shows considerable potential as breeding material due the high biomass productivity, superior ratoon ability, and exceptional adaptability to biotic and abiotic stresses of resulting sugarcane cultivars 5. Despite the importance of the Erianthus germplasm in sugarcane breeding, the large genetic distance between Saccharum and Erianthus results in cross-incompatibility 6-8 , a major constraint in generating intergeneric hybrids. Further constraints arise from the difficulty of distinguishing between genuine intergeneric hybrids and
Cowpea is an important protein primary source in West Africa. To improve both productivity and gr... more Cowpea is an important protein primary source in West Africa. To improve both productivity and grain quality, a rapid, precise, robust, and cost-effective method of estimating the grain nitrogen content of samples grown under various conditions is needed for agronomic and breeding studies. Here, the researchers aimed to 1) develop robust calibration models to predict grain nitrogen content by near-infrared and mid-infrared spectroscopy; and 2) to evaluate the models' adaptability by testing variable samples of cowpea grown in three different agro-ecological zones of West Africa. A total of 251 germplasm accessions with wide variation in grain nitrogen content (2.97% to 5.04%) were used for calibration model development. The new models were validated by using 27 genotypes grown in three locations. The calibration model using both near-infrared and mid-infrared spectroscopy had reasonable accuracy (R 2 = 0.90, RMSECV = 0.07) in cross-validation, and it predicted the nitrogen conte...
Plant Genetic Resources, 2015
Cowpea is traditionally important as an affordable source of protein and minerals and of cash inc... more Cowpea is traditionally important as an affordable source of protein and minerals and of cash income in sub-Saharan Africa, especially for small-scale farmers who have limited options for food and cash crops. The development and deployment of cowpea varieties with improved nutrition and quality that meet the needs of farmers and consumers should enhance cowpea consumption and production in the region. We have identified genetic diversity in various grain quality-related traits of cowpea and relationships among the traits. Wide genetic variation and strong correlations among crude protein, Fe and Zn contents suggest the possibility of improving the concentrations of these nutritional factors simultaneously. Low associations among physical and nutritional properties of grain indicate the possibility of introgressing favorable traits utilizing identified genetic resources. However, narrow variation in amino acid (AA) composition suggests a lesser possibility of improving the contents o...
Biotechnology in Agriculture and Forestry, 2002
Breeding Science, 2006
In order to develop an efficient method of shuttle breeding with rapid generation advancement app... more In order to develop an efficient method of shuttle breeding with rapid generation advancement applicable to the breeding programme of early maturity wheat in the central to southwestern regions of Japan, the possibility of eliminating late heading plants was investigated by combining fall-sown cultivation on Ishigaki Island (24°N), Okinawa, with spring-sown cultivation at Memuro (42°N), Hokkaido. The analysis of heading traits using wheat cultivars and F 2 populations indicated that the earliness of heading in Okinawa and Hokkaido was closely related to both Ppd and Vrn genotypes and the Vrn genotype, respectively. The two hybrid populations segregating for the Ppd or Vrn genes were subjected to rapid generation advancement (F 2 : Okinawa, F 3 : Hokkaido). The analysis of their photoperiod and vernalization responses showed that the plants with photoperiod sensitivity and winter growth habit were eliminated in Okinawa and those with winter growth habit in Hokkaido. The elimination of photoperiod-sensitive plants significantly decreased the proportion of late heading plants in the F 4 population cultivated in the southwestern region of Japan, whereas it was not influenced by the elimination of the winter type plants. It was confirmed that the earliness of heading in the southwestern region of Japan was closely related to the Ppd genotype and was independent of the Vrn genotype, and also indicated that this system of rapid generation advancement was effective in eliminating the late heading plants with photoperiod sensitivity.
Breeding Science, 2005
Genetic analysis of vernalization and photoperiod responses was carried out using eight wheat cul... more Genetic analysis of vernalization and photoperiod responses was carried out using eight wheat cultivars, in order to investigate the relationship between their genotype and the earliness of heading in the southwestern part of Japan. Allelism test of the genes for the vernalization response showed that three wheat cultivars, 'Fukuwasekomugi', 'Zenkoujikomugi' and 'Schomburgk', harboured Vrn-D1, Vrn-D1 and Vrn-A1, respectively. Among the eight cultivars tested, 'Haruhikari' was sensitive to short photoperiod, while the others were insensitive. Segregation analysis of the photoperiod response in the F 2 and B 1 F 1 populations showed that the very late heading cultivar 'Haruhikari' did not harbour major genes for insensitivity to photoperiod. Six cultivars characterized by medium to late heading, 'Norin 61', 'Zenkoujikomugi', 'Saitama 27', 'Schomburgk', 'Norin 59' and 'Norin 67', carried a single gene for insensitivity, Ppd-S, in common. The extremely early heading cultivar 'Fukuwasekomugi' was found to carry two genes for insensitivity, Ppd-S and Ppd-F, the latter displaying a stronger effect for insensitivity to photoperiod. The present study revealed that the earliness of heading in the southwestern part of Japan was closely related to the Ppd genotype of wheat cultivars, whereas it was independent of the Vrn genotype.
BMC biology, Jan 19, 2017
Root and tuber crops are a major food source in tropical Africa. Among these crops are several sp... more Root and tuber crops are a major food source in tropical Africa. Among these crops are several species in the monocotyledonous genus Dioscorea collectively known as yam, a staple tuber crop that contributes enormously to the subsistence and socio-cultural lives of millions of people, principally in West and Central Africa. Yam cultivation is constrained by several factors, and yam can be considered a neglected "orphan" crop that would benefit from crop improvement efforts. However, the lack of genetic and genomic tools has impeded the improvement of this staple crop. To accelerate marker-assisted breeding of yam, we performed genome analysis of white Guinea yam (Dioscorea rotundata) and assembled a 594-Mb genome, 76.4% of which was distributed among 21 linkage groups. In total, we predicted 26,198 genes. Phylogenetic analyses with 2381 conserved genes revealed that Dioscorea is a unique lineage of monocotyledons distinct from the Poales (rice), Arecales (palm), and Zingibe...