The commonly cultivated varieties of peanut (Arachishypogaea L.) are normally classified into three main groups, i.e. Virginia, Spanish and Valencia type. According to this classification, the greater part of cultivated varieties belongr to either of these three types and there are no varieties combined the favourable characteristics which exist inde-pendently in above three types. The object of a series of these studies is to clarify the possibility of the free combination of some characters and to discuss the difEerenciation of cultivated varieties of peanut. In this paper, as the first step to the solu-tion of these problems, the pod-setting percentage in the crosses among three types and some charac-ters of F₁ plants are examined. Results obtained are summarized as follows :

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( I ) There are two Pelargonium species cultivated fcr geranium oil production in Japan, i. e., Pelargonium roseum WILLD. and P. denticulatum JACQ. Pelargonium roseum is superior in the quality of oil (Table 1) and the yield of plant to P.denticulatum, but the former is lower in the yield of oil per plant than the latter. It is very much desirable, therefcre, that the excellent characteristics of both species could be united into one plant by means of hybridization. The hybridization is impossible, however, because they have no functional pollen grains. As mentioned in the foregoing paper (TAMAI et al., 1958), the artificially induced tetraploid of P. roseum became fertile and produced good seeds. In the present paper, the authors deal with the induced tetraploid of another species, P. denticulatum.

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By the morphological and anatomical studies of the stem of wangul (C Iwasakii M. and C glomeratus L.) iri Korea, the following results were obtained 1.The stem of C.Iwasakii is longer and thicker than that of C.glomeratus, and there is not much difference in the stem numbcr between the two species. 2. The shape of a transverse section of stems shows variation from an equiangular triangle to an isoseeles triangle, but there is not fcund any difference between C. Iwasakii and C.glomeratus. 3. In a trarnverse section of the stem at its top, middle and base portions, the largest is the mlddle in C.Iwasaikii and the base in C.glomeratus respectively. The transverse section at the top is the smallest in both species. 4. The shape of sclerenchyma in the cortical layer is concave in C.Iwasakii, but convex in C glomeratus, and the parenchymatous cell in the medullary portion of the stem is fcur or five angular in the former, but roundish in the lattef. These anatomical differences will serve to discriminate, between thetwo species.

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Species crosses using Cucurbifa pepo var. “Nishikikanro" as the staminate parent did not produce F₁ hybnds when the usual open flowver pollinations were made at 7 a.m. on the day of anthesis, probably because pollen germination in this variety is low after anthesis, while the receptivity of the pistillate species is maximum after anthesis The author succeded in making these difficult crosses by storing at lO°C the staminate flowers that harvested at 10 p.m. the day prior to anthesis. All characteristics of these two F₁ hybrids are similar to those of their reciprocal hybrids except for a peculiar fact. From the same fruit of C. maxima x C. pepo two types of fruit shape appeared, differing in the region of blossom-end. Cross-compatiblity of C. pepo var. "Connecticut Field" is high, judging from the successful results of species crosses by several earlier workers, while that of "Nishikikanro" is low in the usual open flower pollination. One of the main causes may be the remarkable physiological changes that occur with different flower age m "Nishikikanro" The production of F₁ hybrids between "Nishikikanro" and two other species was not successful in the usual open flower pollinations at 7 a.m. of the flowering day, but was successful in the following combinations of different ages. 1. Early open flower pollination at 4 a.m.of the flowering day ; C. pepo x C. moschata. 2. Bud pollination at at 7 a.m. of the day before anthesis ; C. pepo x C. maxima. 3. Open flower pollination at 7 a.m. of the flowering day with pollen from male flowers stored at 1O°C from 10 p.m. of the day before anthesis ; C. maxima x C. pepo and C. moschata x C. papo.

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[in Japanese]

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