Germination ability of seeds soaked in various organic solvents was studied in seven species to establish the method for storage of seed in organic solvent. 1) In Raphalnus sativus, seeds soaked in anhy-drous acetone and ethanol for 7 days germinated well, but those soaked in acetone or ethanol con-taning water lost the ability to germinate. For example, seeds soaked in 90% ethanol did not ger-minate at all, but 26% seeds germinated when they were soaked in 95% ethanol (Fig.1). 2) Seeds of Raphaceus sativus, Zea mays, Aster novi-belggi and Oryza sativa had fairly high heat-resistance, e.g. seeds of these species put in an oven and kept at 65°C for 60 minutes germinated as well as untreated seeds as shown in Fig.2. These results suggest that the seeds soaked in organic solvents can be dried in hot condition without injury. 3) Length of heating time needed to volatile solvent from the soaked seeds differd with plant species and the kind of solvent. Seeds soaked in ethyl ether needed 20 minutes in Zea mays and needed 40-50 minutes in Oryza sativa to volatile ether at 45°C (Fig.3). 4) Germination ability of seeds soaked in many organic solvents was tested and compared in four species. Seeds soaked in 32 solvents for 7 days retained the ability to germinate and the seeds soaked in benzene, n-hexane, n-pentane, toluene, carbon tetrachloride, ethyl ether, ethyl acetate, methyl ethyl ketone and acetonitril usually germi-nated better than unsoaked seeds as shown in Table I.

View full abstract

Lots of wild soybean strains (Glycine soja) collected from various parts of Japan were grown in pots at the farm of Faculty of Agriculture, Iwate University, in 1970. The harvested seeds were an-alyzed for protein percentage by macro-kjeldahl method (6.25×N) and sulfur-containing amino acid contents (methionine, cystine, and total, respecti-vely) by micro-biological assay. Potenciality as gene sources for protein improvement of cultivated soybean was discussed. Thereafter in 1972, a part of the strains stated before and the other strains, newly collected from Tohoku district (northern part of Honshu island, Japan), mainly lwate-ken, were grown in pots with similar purpose. Only seed protein percentage was determined.

View full abstract

l. Karyological and cytogenetical studies were made on the interspecific hyprid between Vicia amphicarpa (called V. cordata) 2n=10 aud V.amphicarpa, true 2n=14 in order to clarify the distribution of the parental chro-mosomes in the hybrid progenies. 2. In V.amphicarpa, true, ta₁ the longest subterminal chromosome which possesses a longer short-arm and the ta₃ of the long chromosome which possesses a satellite con-nected to the long arm were identified. The ta₆ is one of the short subterminal chromoso-mes and the ta₇, the shortest submedian chro-mosome, were also identified. In V. amphicarpa (V.cordata), a₂ possesses a short arm which is long compared with the other short arms of other chromosomes; a₄ is the middle sub-terminal chromosome which has a long sate-1lite conneected to the long arm were the identified characteristic chromosomes. 3. In the F₁, the somatic chromosome number was 2n=12, and the a₂, a₄, ta₁, ta₃, ta₆ and ta₇ of parental chrosomes were identified. Almost all external morphological characters of F₁ were intermediate but a few other characters closely resembled to those of V.amphicarpa, true. The growth of AR×Ta F₁ Plants was superior to that of Aw×Ta F₁. The fertility in AR×Ta F_l was consder-ably low and sterile in the Aw×Ta F₁. The chromosome conjugation at M(I) of PMCS Was loose compared with those of the other inters-pecific hybrids of V.sativa and its related species, and many univalent and multivalent chromosome conjugations were observed.

View full abstract

For the purpose of investigation of varietal differences for sulfur-containing amino acid contents in soybean seed protein, and of studying their genetic proprties, 55 varieties grown at Faculty of Agriculture, Iwate University, Morioka, in 1968 and 1969, were used for the determinations of protein percentage by macro-Kjeldahl method (N×6. 25) and the analyses of sulfur-containing amino acid contents by micro-bioassay. The principal results obtained were as follows : 1. The variation among the varieties ranged from 34.8 to 49.1% in protein, frorm 0.67 to 0.96g/16gN in methionine content, from 0.62 to l.22g/16gN in cystine conterit, and from 1.29 to 2.15g/16gN in total sulfur-containing amino acid content. The coefficients of variation (C.V.) were 6.2, 7.2, 14.2, 10.O% in the above four characters, respectively. The extent of varietal differences for sulfur-con-taining arnino acid contents was considered to be equal to or more than for protein percentage. 2. The heritabilities for protein percentage, me-thionine, cystine and total sulfur-containing amino acid contents were 58.8, 55.1, 66.8 and 66.6%, respectively. Sulfur-containing amino acid contents were thought to have almost equal or higher herita-bility values, compared with protein percentage. 3. The varieties, Kosodefuri, Gokuwase-edamame, Gokuwase-hayabusa, Sangowasedaizu and Laredo showed the highest sulfur-containing amino acid contents, which were regarded as of much use as hybridization materials. The varieties Okute-kuro-daizu, and Tairamame were interesting as materials for the studies on soybean protein quality.

View full abstract

Protein content of brown rice of various rice varieties and its relations to agronomic traits were investigated. Statistically significant differences in the protein content of brown rice were observed among cultivars in Japan. The content of protein was approximately 10% higher in brown rice than in polished rice. The protein content was increased by the heavy application of nitrogen. Protein content was nega-tively correlated with the grain yield as well as with the 1000 grain weight, but not correlated with the days to heading and the visual grain quality. A few exceptional cases, however, were observed. For one instance, the two cultivars in the northern part of Japan, “Fukunishiki”and“Fujiminori”, do not differ in their grain yield and heading times, but the former variety contained much more protein than the latter one. For another instance, “Fuku nishiki”and one of the leading varieties in the Japan Sea side area“Honenwase”were both rela-tively high yielding and were top-ranking in the content of protein. An experiment was conducted in order to probe the negative correlation observed between the-protein content and the grain yield.“Kinmaze”is one of high yielding varieties in the central Japan. It contained much less protein than a high protein. mutant N0.217, which bore a small number of grains and was low yielding. The spikelets of“Kinmaze”were clipped to make its sink size equi-valent to that of the mutant strain. Then then the protein content of the high yielding variety was. successfully increased up to the same level as the high protein strain, however, yield was reduced. The reasons for the negative correlation between the above two characters were discussed with reference to the sink and source theory of the carbohydrate and protein accumulation.

View full abstract

Pure-line cultivars and multiline cultivars for disease control Recently, plant breeders have begun to pay atten-tion to the multiline-cultivar concept fcr controlling disease losses in self-pollinated crops. In the past, strict genotypic and phenotypic uniformity was required for the agronomic traits of cultivars, and disease resistance was no exception. When the pure-line cultivar with a single genotype for resistance was widely grown, new races of a patho-gen, that could parasitize this resistance, became selectively more prevalent, and the effectiveness of the newly developed commercial resistance was quickly lost. Plant breeders were forced to search for different resistance genes that were effective against the virulent races. This type of cycle was repeated frequently in the breeding of most self-pollinated crops. Genetic uniformity fcr disease resistance in the host population caused the uni-formity of new virulent reces in the pathogen population. Consequently, the life of a new crop cultivar was oftentimes as short as 3 to 5 years.

View full abstract