[RAPD analysis of the genome evolution in allopolyploid species in Aegilops].

RAPD analysis was performed by applying a set of 24 arbitrary primers to all the allopolyploids and their diploid progenitors in Aegilops L. The analysis based on 313 RAPD fragments revealed that the allopolyploids carrying D genome grouped with Ae. squarrosa (DD) in one cluster. The allopolyploids carrying U genome grouped with Ae. umbellulata (UU) in another cluster except Ae. juvenalis (DDMMUU), which grouped with Ae. squarrosa (DD). The allopolyploids did not cluster with the other diploids. The results indicated that the allopolyploids shared close relationship with Ae. squarrosa (DD) and Ae. umbellulata (UU), respectively. It proved that the D and U genomes altered relatively little from the diploid progenitors after the allopolyploids came into being, but the other genomes changed greatly.

Acoustic signals and acoustic behaviour of Chinese river dolphin (Lipotes vexillifer).

Chinese river dolphin's (Lipotes vexillifer) underwater acoustic signals can be divided into two classes, short-duration signal (pulse train or single pulses) and long-duration signal (whistle). In this paper, time waveforms of these signals are presented and the characteristics of the signals are discussed. The experimental results on this dolphin's acoustic behaviour are given. A sinusoidal pulse with duration of about 300 ms is used as the calling signal. In a certain frequency range, as soon as a calling signal is transmitted the dolphin answers with 2 or 3 whistles. The frequency range of sensitive response is from 4 to 7 KHz, in which the answering rate reaches 100%. When the dolphin's acoustic signals recorded on the tape are transmitted into the water it swims directly toward the transducer. When noise and music are transmitted the dolphin does not respond at all.