So,
1. it is not strange to buy citrus seeds from seedless cultivar, seedless cultivars have seeds too, but very few, for example 1 seed per 20 fruits.
2. Yuzu does not grow true to type from seed.
3. Because of 2. each village has usually its own cultivar.
Lines are called kei
Important selections are:
1.木頭系(きとう)Kitō-kei (kitō)
2.海野系(かいの)Umino-kei
3.早生種の「山根系」Yamane-kei やまねゆず(はやしげる)Yamane yuzu (haya Shigeru)
The Yamane - kei was selected in Mr. Yamane 's garden in Anan City. Fruits are large and flat.
山根(やまね)
4.平の香(たいらのかおり)Hira no ka (tai-ra no Kaori)
seedling which seems to originate from Yuzu in Kinno village, Naka gun, Tokushima prefecture.
The shape of the fruit is somewhat height compared with the conventional type of Yuzu, and the concave ring around the fruit part protrudes considerably in a disk shape, the peel is yellow orange thick , the fragrance is strong.
5.物部系 Monobe-kei
6.種なしの (多田錦(ただにしき)) Tada nishiki