The pollen embryo formation frequency in a C_<17> liquid medium with 0.26M maltose was 4.2〜30.4 times higher than that in the medium with 0.26M sucrose for 12 genotypes of Triticum aestivum L.. The pollen embryo production in liquid C_<17> medium containing maltose was compared with that in liquid Potato 2 medium. The appropriate medium for pollen embryo formation in wheat anther culture differed with ,the cultivar.
In the fermentation of natural indigo, the addition of 0.1 to 0.2 M sodium carbonate not only adjusted pH, but also stimulated fermentation more than did the addition of plant ash extract. When only calcium hydroxide was used for adjusting pH, a reduction of indigo was not caused, suggesting that sodium is required for indigo fermentation. Potassium carbonate did not always show stimulating effects on indigo fermentation. The effects of sodium were confirmed by experiments using sodium chloride as the sodium source, while potassium chloride was not effective. The maximum concentration of sodium carbonate in indigo fermentation was 0.4 M. The higher concentration inhibited the fermentation and the dye solution was liable to spoiling. The optimum concentration of sodium carbonate in the fermentation was 0.1 to 0.2 M. Almost single kind of aerobic, gram-positive rod bacteria were isolated from an indigo dye solution under fermentation on an alkaline agar medium containing 1% sodium carbonate, pH 11. The isolated bacteria showed salt resistance to as high a concentration of sodium chloride as that of sea water but could also grow without sodium, sugggesting that sodium is not necessarily required for growth, but is required to reduce indigo in anaerobic respiration under low oxidation reduction potential.
Two plasmids, pBT323 and pBT626, carrying the insecticidal protein gene of Bacillus thuringiensis subsp. aizawai IPL7, were constructed. The plasmid pBT323 was the derivative of the binary vector pBI121, but had the insecticidal protein gene instead of the β-glucuronidase gene and was able to replicate in Escherichia coil and Agrobacterium tumefaciens. This plasmid had border sequences of the Ti-plasmid of A. tumefaciens, and the NPTII gene (with the NOS promoter and the NOS terminater) and the insecticidal protein gene (with the CaMV 35S promoter and the NOS terminater) were between its border sequences. So it could be expected that the DNA sequences between border sequences of the plasmids pBT323 were able to be inserted into nuclear DNA by A. tumefaciens to cause plants to express insecticidal proteins. The plasmid pBT626 was constructed by replacing the /?-glucuronidase gene of the plasmid pBI221, a derivative of the plasmid pUC119, with the insecticidal protein gene. It had the insecticidal protein gene between the CaMV 35S promoter and the NOS terminator and was able to replicate in E. coil.