In Hokkaido, wheat varieties have been improved and the yield and quality have increased markedly, but not so much progress has been made in other part of Japan. In Kanto, Tokai, and western Japan, varieties for Japanese noodle were the main objective of wheat breeding. But now, wheat produced in that part of Japan is used mainly for cake. So we have to review the objective of wheat breeding. Recent years, wheat quality improvement has been the main issue and the quality characteristics such as grain hardness and glutenin have been studied intensively. On the other hand, the yield and the disease tolerance have not been considered big issue, which now have to be paid much attention. Other than the review of breeding target, the importance of expanding genetic diversity has to be emphasized.
Morphological and physiological characters of a common reed (Phragmites australis (Cav.) Trin. ex Steud.), cultured in a greenhouse, were investigated using 12 lines corrected from Shiga Prefecture. There were 3 and 4 times differences in the emergence of shoot and root from a node, respectively. Days to emergence of shoot and root were also different among the lines used in this experiment. Further characterizations were carried out using 4 lines, which had been shown to be easy to culture and propagate and demonstrated the clear differences in shoot/root biomass and uptake ability of nutrients such as nitrate and phosphate.
The natural habitat of the Echinochloa species growing in eastern Australia was investigated in May 2008. In this survey, four annual native species, E. dietrichiana, E. inundata, E. telmatophila, and E. turneriana, and three exotic species, E. colona, E. crus-galli, and E. polystachya, were observed. The native species clearly have separate habitats: permanent stagnant pools for E. dietrichiana, inland floodplains for E. inundata, in or beside streams for E. telmatophila, and inland watercourses for E. turneriana. While the habitat of the exotic species greatly overlap that of the natives, especially perennial E. polystachya, which forms monospecific stands in stagnant pools and in or beside flood rivers due to its remarkable productivity, and E. crus-galli, which has the potential to adapt to several moisture conditions. We predict that the invasive exotic Echinochloa species will become more and more threatening causing serious damage to the native species within the same genus.
This study investigated disease occurrence of Phytophthora stem rot of soybean (caused by Phytophthora sojae) in Glycine max (L.) Merr. cv. Tanbakuro producing areas in Hyogo from 2005-2007, pathogenic races of P. sojae, and effectiveness of five Rps genes and eight soybean cultivars to several races. Disease incidence at 93 different fields in seven regions of Hyogo ranged from 3.3 to 23.5% in 2005 to 2007. Ninety-three isolates of P. sojae were recovered from the 93 fields. Six Japanese differential soybean cultivars were used for race determination of the 93 isolates with the agar medium inoculation method. The results showed that race E was a major component of all the P. sojae population, followed by races A, L, K, M, G, N and new race O. This result was subsequently integrated with the previous data with 51 isolates derived from 2002-2004. Race E tended to be dominant from 2002-2007 throughout seven regions of Hyogo. Cvs. Enrei, Sachiyutaka, Rps6 in cv. Altona, Rps1a+Rps7 in cv. Harosoy 63, and Rps1k in cv. L77-1794, considered to be strongly resistant in the USA, were susceptible to most of 144 isolates, suggesting that they were ineffective. Rps1d in cv. PI103091 was not defeated by the 144 isolates, nor was cv. Gedenshirazu-1. Cv. Ohojyu was resistant to 140 of the 144 isolates. These results indicate that three soybean cultivars were still potential sources of resistance to breed new resistant cultivars with the desirable characteristics of cv. Tanbakuro.
A water budget equation model was developed to support farmer's decision for irrigation to his fields in the previous study. This study applied the model to farmer's fields actually, and evaluated a method to estimate model parameter for available water holding capacity (AWHC). Since the estimated volumetric soil moisture content (SMC) was well correspondent with the measured SMC, the model was able to evaluate the fluctuation of water availability in farmer's fields. Rate of available water (Aw) to AWHC (Aw/AWHC) calculated from the model was linearly related to change of instrument reading per day (ΔIR) in the simple soil moisture measuring system developed by Kurose (2006). In order to estimate AWHC, changes of instrument readings (IRs) for 3 periods were necessary for each field. Estimated AWHC varied from 24 to 73mm among investigated fields, and the value made it possible to predict daily change of IR. It is important to enhance reliability on the basis of more data.
The objectives of this study were to evaluate the main effects and interactions of individual quantitative trait loci (QTLs) for grain length and their combinations in rice. Five primary near-isogenic lines (NILs), each of which had an allele for long grain only at one of five QTLs controlling grain length of a large-grain cultivar, 'BG 1', and an allele for short grain length at the other four QTLs, were constructed with a common genetic background of a small-grain cultivar, 'Gimbozu'. In addition, an NIL involving a major gene for long grain of 'Fusayoshi', Lkf, in the same background as above was developed. From intercrossing of these primary NILs, phenotypic selection, and progeny tests, 15 advanced NILs, each of which had different alleles for long grain only at one of the 10 combinations of five QTLs, and one of the five combinations of five QTLs and Lkf, were further constructed. The main effects (additive effects) and interactions (epistatic interactions) of QTLs and Lkf on grain length were estimated from the mean grain lengths of these NILs and 'Gimbozu' cultivated over two years. The main effect of Lkf was the largest, followed by those the QTLs showing a large and significant variation among them. The correlation coefficient between the two years for the main effects was high and significant (r=0.95*), suggesting that the QTLs' main effects were consistently expressed at their own magnitudes for the two different years. The interactions between two QTLs were about half the strength of the main effects in their magnitudes and also showed a large, significant variation among QTLs. The year-to-year correlation for the interactions was, however, not significant (r=0.63). These results suggested that QTL-by-QTL interactions could contribute to the instability of character expression and could play an important role in genetic systems controlling quantitative traits.
To make the rice cultivar 'Kozo-no-sumika' with a beautiful figure at the flowering time late ripened, it hybridized with ultra early ripened rice plant. The form and the genetic nature were investigated about the posterity of the crossbreed. As a result, being ruled by single inferiority and each dominant gene became clear from the morphological characteristic investigation as for the presence of the plant length and the awns. The length of glumes was thought for the possibility of rule by a single recessive gene to exist. The purple coloring matter synthesis's in the leaf being ruled by an independent two dominant supplementation gene became clear. It was suggested to show the incomplete dominance about ear emergence by a single gene. In the strain selection, it was suggested that the selection be able surely to be advanced. The difference between genotypes of the regenerated plant has grown in the anther culture. The possibility of succeeding the genotype and depending on the selection of the kind of the medium was suggested this time though the reproduction individual of F1 was not obtained.