BERLIN — (vis) — Berliners~— many of them from the Soviet sector—who last night saw the George Gershwin opera. Porgy and Bess, today wondered aloud if Negro talent is neglected in the U. S., as the Soviets say. Two thousand Berlin residents, some of whom were on line two hours ahead of time, cheered and applauded the performance of the opera, sent as America’s contri bution to the city’s cultural fes tival. Included in the all-Negro cast, Which was the same one which won high praise in Washington, D. C.,, are William Warfield as Porgy, Leontyne Price as Bess and Cab Calloway as Sportin’ Life. One East Berliner was over heard to say after the performance that Soviet tales of neglected Ne gro talent are “as big lies as ev erything else they say.”