We compared the growth characteristics and starch productivity among three major sago varieties (folk varieties), namely Molat (spineless), Tuni (spined), and Rotan (spined), grown near Kendari, Southeast Sulawesi Province, Indonesia. Growth characteristics of the three varieties were compared in relation to years after trunk formation (ATF). All the three varieties reached the trunk formation stage at 3 to 4 years after sucker planting or emergence. However, Molat and Tuni reached the flowering stage at 8 to 10 years ATF, whereas Rotan reached the flowering stage at 6 to 7 years ATF. The trunk length and trunk weight increased with increasing years ATF, and the trunk elongation rates were almost the same in the three varieties (1.0-1.1 m/year). However, the increase in trunk weight per year ATF differed markedly among the three varieties as follows; Molat (233 kg), Tuni (181 kg), and Rotan (90 kg). At the harvesting stage, the average trunk weight was 1823 kg in Molat, 1399 kg in Tuni, and 566 kg in Rotan. On a dry weight basis, the starch percentage in the pith increased from 1 to 3 or 4 years ATF in Rotan and from 3 to 7 or 8 years ATF in Molat and Tuni. In all the varieties, the starch percentage reached 60-70%. Starch accumulation began in the first year ATF in Rotan, but began at approximately at 4 years ATF in Molat and Tuni. Once starch accumulation had begun, it continued at a constant rate in all the varieties (81, 62, and 28 kg/palm/year in Molat, Tuni, and Rotan, respectively). At the harvesting stage, the average starch yield was 425 kg in Molat, 305 kg in Tuni, and 142 kg in Rotan. These differences resulted from differences in the trunk (pith) weight.
An AFLP-based genetic linkage map of diploid Ipomoea trifida was constructed using the F1 mapping population from the cross between two lines, ‘0431-1’ and ‘Mx23-4’, as the maternal and paternal parents, respectively. Based on the “pseudo-testcross design” for analyzing F1 populations from heterozygous parents, the genotype data of the AFLP markers were split into maternal and paternal datasets, and separate genetic linkage maps were constructed. The maternal map was comprised of 618 markers on 17 linkage groups with a total map length of 910.0 cM per haploid, which approximately corresponds to one-sixth of the total map length of the hexaploid sweetpotato map. The paternal map consisted of 163 markers mapped on 15 linkage groups covering a total map length of 503.3 cM. The genetic linkage map presented here is the first step to construct a diploid-level reference linkage map which will be useful for analyzing the allelic relationship(s) of gene(s) controlling important agronomic traits.
As a major factor for the attainment of the “Green Revolution” in Sub-Saharan Africa, wide attention has recently been paid to new cultivars of rice, called NERICA. Though the diffusion of NERICA had been rapid, planting is being discontinued by many farmers after a few years. An important issue for NERICA dissemination is how to extend the duration of adoption. In the present study, the determinants of NERICA adoption were identified by the method of duration analysis, based on data collected through interview surveys of farmers in Uganda. We observed that farmers discontinued NERICA production at early stages of the adoption process and that drought occurrence and long distance to rice mills decreased the adoption duration of NERICA, while membership of farmers’ groups contributed to the continuation of NERICA adoption. Our study suggests that in order to promote the adoption of NERICA in Sub-Saharan Africa, it is essential to reduce the fluctuations in rice yield due to erratic weather conditions through the implementation of water control measures, the development of post-harvest markets, and membership of farmer groups that maximize “social learning.”
Citrus keraji hort. ex Tanaka var. kabuchii (‘Kabuchii’) originates from Okinawa, and has been cultivated in the Okinawa Islands for hundreds of years. However, the components responsible for its characteristic fresh aroma have not been determined. ‘Kabuchii’ is used as a table fruit and also in the production of traditional sweets and juice. At present, the residues produced during the manufacturing process are underutilized. In the present study, we extracted the essential oil from ‘Kabuchii’ peel residues using different extraction methods and characterized its aromatic components by gas-chromatography/mass-spectrometry. We identified 70 aromatic components in the essential oil of ‘Kabuchii’, and found that different extraction methods gave oils with a similar composition. Our results suggest that the residues from citrus processing factories could be used for the manufacture of other products, e.g., aromatherapy, food, flavor, and cosmetic products. The results of present study provide data that could be used by the citrus industry to develop new ‘Kabuchii’ products.