Virginia Democrats, appealing to traditional values with a nontraditional ticket, today nominated state Attorney General Gerald L. Baliles for governor and, for the first time, placed a black and a woman on their state slate.

In a convention that played down doubts and celebrated unity, the Democrats chose state Sen. L. Douglas Wilder of Richmond for lieutenant governor, the first black statewide candidate of a major party in Virginia, and Del. Mary Sue Terry of rural Patrick County for attorney general.

"We have the ticket for Virginia," proclaimed Democratic Gov. Charles S. Robb to a cheering crowd of about 3,500 Democrats. Robb's name and popularity repeatedly were invoked by the Democrats, who hope to repeat their 1981 sweep of the three statewide offices.

The unique Democratic ticket is braced to compete against a sharply conservative GOP ticket headed by Wyatt B. Durrette, a Richmond lawyer, in an election that will test the staying power of the Democratic coalition that elected Robb as Virginia's first Democratic governor in 12 years.

Political analyst Larry J. Sabato of the University of Virginia called the ticket "really revolutionary" for Virginia. "It's a Southern state and is one of the most conservative."

Because only New Jersey and Virginia have elections this fall, the Baliles-Durrette race is expected to attract national attention. Republicans have already announced that President Reagan will campaign here for their slate.

Wilder, 54, in a speech that was greeted with applause and cheers, emphasized his ties to the state rather than his race. He said he "asked for no special favors" and pledged that "this is one Virginian who never has and never will lose faith in Virginia."

Baliles, 44, a former state legislator from Richmond, used his acceptance speech to thrash and ridicule a Republican Party "of closed minds and closed doors . . . . "

Speaking to the cheering, sign-waving Democrats who met here in unaccustomed unity, Baliles said Durrette and his GOP running mates "offer a narrow and negative vision which looks backward and to the far right." Baliles defeated Durrette for attorney general in 1981.

Durrette, a former legislator from Fairfax County, was nominated last weekend at the GOP convention in Norfolk, which chose state Sen. John H. Chichester of Fredericksburg for lieutenant governor and Virginia Beach Del. W.R. (Buster) O'Brien for attorney general.

Robb, in remarks that foreshadowed a tough and grueling campaign, warned that the Republicans "are going to bait us and they're going to bash us." But he said: "None of this is going to work."

The Democrats peppered their acceptance speeches with references to what they called the Robb "legacy." Baliles mentioned Robb's name seven times in his 15-minute speech.

In addition to cultivating traditional Democratic supporters, Baliles said the party will aggressively attempt to encroach on Republican territory.

Casting his ticket as one that will appeal to mainstream moderates, Baliles said, "We shall invite the Republican refugees from the Mountain Valley and the suburbs into our party."

The GOP ticket does not include anyone from the state's Roanoke and Shenandoah valleys, traditional areas of support for moderate Republicans and areas that have had a representative on the GOP ticket since the late 1940s. J. Marshall Coleman, a former legislator from the region and the party's 1981 nominee against Robb, said yesterday that he had rejected overtures by his supporters to run this fall as an independent for governor. Coleman, who lost his bid to be on the GOP ticket, said he will support his party's ticket.

The Democratic ticket may face an equally serious geographic problem because it does not have a representative from either the populous Northern Virginia or Tidewater regions.

Some Democrats said another major hurdle will be raising the $3 million that the party expects it will need to compete against the Republicans in what is expected to be the most expensive campaign in state history. "Our biggest challenge is to raise the money," said state Sen. Edward M. Holland (D-Arlington).

During the two-day Democratic convention at the Richmond Coliseum, a number of delegates questioned each other over whether their ticket will remain unified if one of the three candidates becomes a liability.

State Sen. Joseph V. Gartlan (D-Fairfax) said those concerns focused more on Wilder than Terry. But he said: "That's a double-edged sword. It could cut into the black support, and I don't think Baliles or Terry can afford to give any of that away."

State Del. Alan A. Diamonstein, the retiring state Democratic chairman, insisted today the Democrats will run "as a team" but said the nominees are individuals responsible for their own campaigns. The Republicans have pledged to run as a team for all three offices.

The convention was treated to frequent snipes at the Republicans who have been embarrassed by glitches in their campaigns.

"The Republicans are for Metro just like Buster O'Brien is a Washington Redskin," Baliles said, referring to the fact that O'Brien had claimed to be a member of the team although he never started a game.

Baliles, usually reserved and soft-spoken, joked about the Durrette campaign's decision to destroy 20,000 bumper stickers because they had a small union label on them. "This campaign is not a contest of bumper stickers, but a contest of ideas," Baliles said.

The attorney general said he will campaign on the issues of improving transportation -- including funding of the full proposed 101 miles of the Metrorail system in the Washington area, education and continued economic development.

In one bittersweet moment, Baliles was nominated by the man he defeated for the nomination weeks before the convention.

Lt. Gov. Richard J. Davis of Portsmouth, who spent more than $1 million in his unsuccessful bid for the nomination, praised Baliles as a "special friend" who would take the party's campaign "to the front porches and back yards of all Virginians."

The Democrats demonstrated an eagerness to match the Republicans who flaunt "family issues" at their convention. Republican O'Brien particularly has emphasized his marriage and family, an indirect way of pointing out that Terry is unmarried.

Terry today was nominated by her father Nate, a farmer and former schoolteacher in Patrick County, and was surrounded by her parents, sisters, cousins and inlaws after her speech.

"You want family to be an issue?" shouted House Speaker A.L. Philpott, the convention chairman. "This is just a small portion of what we can bring out of the hills and hollows of Patrick County."