White mold (WM) caused by Sclerotinia sclerotiorum (Lib.) de Bary is one of the most harmful diseases on a number of crops, including common bean. Its harmful effect on bean is affected by the growth habit, crop production practice and by the physiological resistance of the cultivars (Schwartz et al., 1987). Combining physiological resistance with mechanisms for prevention of infection and pathogen development (erect plant, open plant canopy) is the current breeding strategy for minimizing yield losses due to white mold in common bean (Miklas et al., 2000).

The resistance of common bean to Colletotrichum lindemuthianum is controlled by a number of race-specific genes. To combine various genes for resistance to anthracnose alternating crossing was performed. The resulting recombinant inbred lines (RILs) are based on the cross DG 2-36 [Red Hawk/TO//AB136/3/Red Hawk/TO//TU/4/DG 98-53]. Breeding for resistance to C. lindemuthianum using several physiological races of anthracnose identified in Bulgaria was performed from F-1 to F-5 generation. Seven RILs of F, progeny, possessing more than one specific gene for resistance were selected by RAPD and SCAR markers linked to Co-1 and Co-4 genes. The line DG 2-36-58-3 was determined as the most promising by quality complex of growth habit type, vegetation period, type of seeds, yield and presence of Co-1 and Co-4 genes that confer resistance to 74 out of 78 worldwide recognized anthracnose races.Several common bean varieties with useful breeding traits were investigated as a source of Co-2 specific gene. Cultivar 'Drezden' and the new Bulgarian variety 'Beslet' carrying of two genes for resistance in the Co-2 locus were determined as promising sources of the gene for the future breeding programs to obtain durable resistance to C. lindemuthianum.

Bacterial wilt is one of the three bacterial diseases on dry bean in Bulgaria. The disease is caused by the bacterium Curtobacterium flaccumfaciens pv. flaccumfaciens. The bacterium causes stunting, wilting and death of the bean plants. The disease development is favored by hot weather and drought stress. Breeding varieties combining resistance to common bacterial blight, halo blight and bacterial wilt is the main strategy for control of bacterial diseases on bean in Bulgaria; this strategy is incorporated in the breeding program of DAI General Toshevo. In our preliminary study we determined several sources of resistance to individual strains of C.f. pv. flaccumfaciens (Kiryakov and Genchev, 2000). This publication presents results on the testing for resistance of elite accessions and breeding lines of dry bean to bacterial wilt.

CdO whisker crystals with micrometre thickness and length of up to 4.5 mm were grown by a simple technology described in previous publications of the authors. The whiskers grow on CdS crystal substrates, previously covered by a thin metal or silicon layer, on annealing in air at atmospheric pressure. The growth initiator used was Ag, Au, AI, Si, Mn, Ni, Pd or Pt. A study was carried out of the effect of impurities on the conditions and efficiency of growth, as well as on the morphology and composition of the whiskers obtained. The small crystals were examined using an optical microscope, a scanning electron microscope, X-ray structural analysis and X-ray microanalysis. The maximum speed of growth obtained with Au was about 1 mm h−1. The whiskers grow with a face-centred cubic lattice. The largest crystals are in the form of a parallelipiped with facets of {100}. Data are obtained which support the vapour-liquid-solid mechanism of crystal growth. The possibility is also shown of growing whiskers on zinc or cadmium plates covered with a thin layer of Cu, Ag, Au or AI by applying the same technology.

The in vitro and in vivo effects of cis-diamminedichloroplatinum(II) (cis-DDP), transdiamminedichloroplatinum(II), spermine-platinum(II) complex and K2PtCl4 on the RNA polymerase reaction in isolated nuclei from Ehrlich ascites tumour cells were investigated. Incubation of nuclei in the presence of platinum compounds did not substantially influence the RNA polymerase reaction. The results from the in vivo experiments (i.e. after i.p. injection of mice with platinum compounds before nuclei isolation) showed that the compounds displayed distinct inhibitory effects on the reaction which was most pronounced with K2PtCl4 and cis-DDP.

A way of growing cadmium oxide whiskers is described. The whiskers were grown on CdS single crystal substrates having a palladium film (d ∼ 10 to 30 nm) deposited on the surface, upon annealing of the samples in an argon atmosphere with small oxygen impurity, at temperatures 580 to 640° C, for 2 to 4 H. The whiskers have micron sizes: a cross-section of several square micrometres, length from several tens to several hundreds of micrometres. The composition (CdO) and structure of the whiskers have been determined by X-ray microanalysis and reflection high energy electron diffraction. The main crystal forms studied by SEM, are described: tetragonal prisms, needles, threads, prisms with a faceted formation on the upper base, plates. On the basis of the data from electron diffraction and SEM as well as the comparison with literature data, it is established that the predominant orientation of growth is 〈1 00〉.