Inbreeding in Diploid and Amphidiploid Dendrobium

Nine inbred progenies derived from amphidiploid Dendrobium Jaquelyn Thomas ’Y166-1' and one noninbred progeny were studied. Selfings, sibmatings and backcrosses were done using individuals randomly chosen or selected for larger flowers having a low amount of pink tinge on the white petals and sepals. Vigorous plants of each progeny were selected for cultivation. Selection coupled with inbreeding was successful in increasing flower size and decreasing the degree of pink tinge. This process of selection and inbreeding effected a decline in yield (number of harvested racemes) from the S1 to the S3. Inbreeding decline was not apparent in the characters of scape length, raceme length, number of initiated flowers per raceme, percent bud drop and vase life; the genetic constitutions of the parents seemed to determine the nature of these characters in the progeny. It was not clear to what extent inbreeding affected shoot height. Dry weight measurements were taken for progenies from selfing D. d’albertsii, D. schullerl, D. phalaenopsis and D. Jaquelyn Thomas. Plants were dried and weighed when in the flask stage of growth and a mean plant dry weight was calculated for each flask. No inbreeding depression was observed in progenies of five generations of selfing a diploid D. d’albertsii. Due to a tendency of the protocorms to proliferate, it was difficult to assess any difference among the D. schulleri inbred progenies. Inbred progenies of amphidiploid D. Jaquelyn Thomas '2085-4N' and amphidiploid D. Jaquelyn Thomas 'Y166-1' did not display inbreeding decline. Two S2 progenies of D. phalaenopsis 'Kosaki' gave significantly lower dry weight measurements than the S1 progeny while one S2 progeny did not differ from the S1

The Leakage Neutron Spectrum of a Spherical Critical Assembly of U233

In this paper the spectrum of the neutrons escaping from a critical sphere of U233 is investigated experimentally and theoretically. The experimental investigation involved exposing a nuclear emulsion to the neutron flux and, after development, examining the details of the proton-recoil tracks visible in the emulsion

The Effects of Selection and Inbreeding on Early Yield and Flower Quality in Amphidiploid Dendrobium

Ten progenies involving self-, sib-, and backcross matings and an outcross were compared to determine the effects of inbreeding and selection in amphidiploid Dendrobium Jaquelyn Thomas. The progenies included two sets of reciprocal matings. The measurements of yield, size, and earliness of flowering indicated a decline due to inbreeding. Selection increased flower size and improved the purity of flower color. Detrimental effects of inbreeding on these characters were not detected. Significant differences were obtained for keeping quality, number of flowers per spray, and length of the scape of the spray. However, it was not possible to attribute these differences to either inbreeding or selection effects. Spray length differences were nonsignificant. Offspring of reciprocal crosses did not differ significantly in all characters measured

Automatic generation of RESTful interface

katedra počítačové grafiky a interakc