The effect of Ca++ on pollen germination and tube growth in various angiosperm species was studied in vitro culture in relation to other cations and water-soluble substances which enhanced the Ca++ action. 1) The Ca++ added to the standard culture medium containing boron and sucrose markedly promoted pollen germination and tube growth. In some cases, pollen of certain species failed to germinate in the absence of Ca++ in the media. 2) The effect of Ca++ on pollen growth was much improved by the addition of some other cations, such as Mg++ and K+. 3) In the presence of Ca++, the rate of pollen growth was increased by an increased level of Mg++ and/or K+, just as did an increased level of Ca++ when the level of Mg++ and K+ was kept constant. The interaction between these cations seems to bring about an improved pollen growth. 4) The action of Mg++ and K+ in support of the Ca++ effect was replaced almost completely by other soluble inorganic and organic substances in lower concentrations. 5) The response of pollen growth to various levels of Ca++ differed greatly among the different species tested. This showed that the pollen of certain species requires different amounts of Ca++ in the process of pollen growth.
Description and drawings of the second species of Echinocolea Schust. 1963: E. herzogii Mizut. et Gro. sp. nov. from Celebes. Echinocolea is new to Asia and the whole palaeotropic region. Notes on intercalary branching of leafy hepatics. Four types were discriminated: Bazzania type, Plagiochila type, Anomoclada type and Lejeuneatype.
When the detached leaves of Elodea densa were cultured in tap water in the dark, chloroplasts were subjected progressive degeneration. After 5 days they became small in size and yellow in colour, having several yellowish particles. Under electron microscope, the lamellar structure was degraded irregularly as the senescence proceeded, in which case the degradation of stroma lamellae seemed to occur earlier than that of grana lamellae. Moreover, it was found that some osmiophilic granules used to appear in the chloroplast. Those granules obviously correspond to the yellow particles observed under the light microscope. They reacted to produce a deep blue to blue-green colour by treatment with 75% H2SO4 and also showed a conspicuous iodine reaction. They are soluble in chloroform, methanol, carbon disulfide but insoluble in acetone and petroleum ether. Therefore, it seems that some carotenoid pigments in lamellar structure were liberated and transferred into these granules. Probably, this may be identified as “eloxanthin”. as previously called by Karrer.
Some forms of bread wheat with branched ears were obtained by continuous selections of MR 1 strain, which was formerly produced by the cross between the non-branched soft wheat 'Martin's Amber' and 'Red genealogical'. The breeding work began in 1955, when the double spikelet structures were found in the normal ear. Then those ear abnormalities were accumulated in plants generation to generation, with a final formation of branched ears. The deformed characters were found to be cumulative and heritable in the offspring. The factors concerning the appearance of branched ear were in the relationship between growth and development as reported by Lysenko and under a strong influence of nutritional conditions.
1. The author studied distribution and habitats of Kalimeris indica in the region comprizing the Tane-ga-shima Island and the Osumi and the Satsuma Peninsulae of Kyushu. Morphological and cytological studies were made on approximately 200 clones collected from there and some other localities of the Nansei-shoto Islands. 2. Populations of K. indica were observed in many localities of the Tane-ga-shima Island and the Osumi Peninsula. They occurred also in some localities of the Satsuma Peninsula. Beside the common type of K. indica, hybrid types were found in the Tane-ga-shima Island and both of the peninsulae. 3. The common type was typical and constant in external morphology and ecological preferance, whereas the hybrid types were more variable and contained certain characters or character combinations which suggested their affinity to either a species of Aster orK. yomena. 4. Most clones of the common type were hexaploids with 2n=54, while a few clones were aneuploids with 2n=52, 53, 55 and 56. Clones with 2n=54 were also the most typical of the hybrid types. 5. Somatic chromosomes of the common type were observed at prometaphase as well as at metaphase. The karyotype at metaphase showed no variation indicating geographical significance. Some of the chromosomes being similar to each other in appearance at metaphase were found to have different structural features at prometaphase. 6. The hybrid type which suggested its affinity to K. yomena in some morphological characters was indistinguishable in karyotype from the common type of K. india. The other hybrid type had karyotypes with or without large chromosomes from Aster. The karyotype with large chromosomes was of unbalanced one, whereas those without large chromosomes were closely similar to that of the common type. 7. The common type showed regular meiosis, forming 27 bivalent chromosomes in the majority of PMCs. Meiosis was also regular in the clones of the hybrid types when they had karyotypes closely similar to that of the common type. Meiosis was highly irregular in the clones having large chromosomes from Aster.