CATALINA ISLAND, Calif. — Funeral services have been held here for Robert Berning, the principal wine buyer for Trader Joe's during its early years who established the chain's trademark low-cost wine offerings. Berning, 73, died of bone cancer. He was working for King Cole Markets, a Southern California independent, where he developed his interest in imported wines, when he was hired as a store manager in 1965 by Pronto Markets, Trader Joe's predecessor company. When Trader Joe's shifted its merchandising to focus heavily on wine in 1970, Berning became the chain's principal wine buyer, developing a private-label program for wines that enabled the company to sell at low prices during a time when most wine pricing was covered by fair-trade laws. He retired from the company in the mid-1990s and eventually became a consultant for Plume Ridge, a wine importing company owned by his daughter. Berning is survived by a son, two daughters, two sisters and 13 grandchildren.