Is it possible to linear-gradient-fill a grouped path in SVG (by css or attr on jQuery event)

How can i fill one gradient for a <g> in an SVG image instead of fill all the <g>s in the selected <g>?

In this case, I'd like to show africa, filled with just one gradient from yellow to red, but because of the sub-groups the fill makes many of gradients.

The javascript:

<script type="text/javascript">
function svgOver() { 
    var what = $(this).attr("id");
    $("#world #"+what, svg.root()).attr("fill", "url(#red_black)"); 
} 
function svgOut() { 
    $(this).attr("fill", "");
}

...

$("#map").svg({ 
    loadURL: 'http://teszt.privilegetours.hu/skins/privilege/svg/worldmap.svg',
        onLoad: function(svg) { 
        $("#world > g", svg.root()).bind('mouseover', svgOver).bind('mouseout', svgOut).bind('click', svgZoom);
        },
    settings: {}
});

The SVG:

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" mlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" width="570px" height="300px" viewBox="146.605 71.42 570 300" enable-background="new 146.605 71.42 570 300" xml:space="preserve">

<defs>
    <linearGradient id="red_black" x1="0%" y1="0%" x2="0%" y2="100%">
        <stop offset="0%" style="stop-color:rgb(255,0,0);stop-opacity:1"/>
        <stop offset="100%" style="stop-color:rgb(255,255,0);stop-opacity:1"/>
    </linearGradient>
</defs>

<g id="world" transform="scale(1)" fill="#AAAAAA" stroke="#FFFFFF" stroke-width="0.1">
    <g id="africa" name="africa"> // < i want to fill this
        <g id="er" transform="translate(-29.9017, -45.0745)"> // < instead of theese
            <path d="..."/>
        </g>
        <g id="yt"> // < instead of theese
            <pat