Table 3.

Avirulent Fungus/Mutant Pairs Identify Pi-ta and a Second R Gene in Rice Varieties with Pi-ta²

Rice Variety	O-137 AVR-Pita	CP3337a	Pi-ta Presentb	O-135 AVR-Pita2	CP753c	Second R Gene Presentb
Yashiro-mochi	AVR	Vir d	+	Vir	Vir	−
K1	AVR	Vir	+	Vir	Vir	−
Tadukan	AVR	Vir	+	AVR	Vir	+
Tetep	AVR	Vir	+	AVR	Vir	+
Reiho	AVR	Vir	+	AVR	Vir	+
Katy	AVR	Vir	+	AVR	Vir	+
C101A51	Vir	Vir	−	AVR	AVR	−
YT16	Vir	Vir	−	Vir	Vir	−

^aCP3337 is a spontaneous mutant of O-137 that has lost AVR-Pita.

^b(+), present; (−), absent.

^cCP753 is a spontaneous mutant of O-135 that gained virulence toward varieties containing Pi-ta². Specificity of CP753 is not altered toward a third R gene, Pi-2.

^dVir, virulence.