RESUMO
Phytophthora capsici from seven provinces of China were investigated for their mating type, hyphal growth, zoospore production, and virulence. All of the morphological characteristics and the results of polymerase chain reaction confirmed that these isolates were indeed Phytophthora capsici. The test of mating type showed that the mating types of 19 representative isolates from China varied. The hyphal growth and the amount of zoospores produced from these isolates differed and there was no evident relationship between them, which indicated the existence of genetic diversity among the isolates in China. Also, the isolates that were more virulent on the pepper cultivars that we checked produced more zoospores than other isolates.
Assuntos
Phytophthora/genética , Capsicum/microbiologia , Phytophthora/isolamento & purificação , Phytophthora/patogenicidade , Phytophthora/fisiologia , Reprodução/genética , Esporos/genética , Esporos/fisiologia , Virulência/genéticaRESUMO
Here we have used gene-targeting to eliminate expression of smooth-muscle myosin heavy chain. Elimination of this gene does not affect expression of non-muscle myosin heavy chain, and knockout individuals typically survive for three days. Prolonged activation, by KCl depolarisation, of intact bladder preparations from wild-type neonatal mice produces an initial transient state (phase 1) of high force generation and maximal shortening velocity, which is followed by a sustained state (phase 2) characterized by low force generation and maximal shortening velocity. Similar preparations from knockout neonatal mice do not undergo phase 1, but exhibit a normal phase 2. We propose that, in neonatal smooth muscle phase 1 is generated by recruitment of smooth-muscle myosin heavy chain, whereas phase 2 can be generated by activation of non-muscle myosin heavy chain. We conclude that phase 1 becomes indispensable for survival and normal growth soon after birth, particularly for functions such as homeostasis and circulation.
