Just as the music and fashions of earlier decades are being taken for another spin in the 1990s, so old wine grape varieties are being eyed again by UC agricultural scientists.Among those being considered for introduction to California vineyards are black varieties from southern France that have demonstrated excellent potential for red-wine production, according to Pete Christensen, a UC Davis Cooperative Extension viticulture specialist at the UC Kearney Agricultural Center in Parlier. And several varieties from northern Italy are also impressive, he says.While scientists are studying other varieties for California production, Christensen suspects many of the state's growers are already planting some of these old European varieties, hoping to get an edge on their competition.