Bud mutation is an important form of plant improvement in persimmon. Bud mutation of major cultivars has resulted in a number of valuable selections being identified in Japan. Early ripening selections have helped to extend the marketing period for Japanese growers. Most bud mutations have been identified by growers. They are characterised by changes in fruit size, shape, brix, maturity, cracking and tree vigour (Table 1, 2). Some selections are known and used only within a locality and provide a competitive edge against other grower groups. By top-working old trees a Japanese grower can rapidly convert to new selections without a major loss of income as trees can return to full production within four years. Many of the selections have been patented and may require licensing agreements with a New Zealand agency or nursery before they are made available to the local industry.

Most persimmon bud-sports have probably arisen as periclinal chimeras with the initial mutation occurring in the epidermal layer. Support for this idea is given in breeding studies at Akitsu Branch of the National Fruit Tree Research Station. Both Fuyu and the early ripening bud-sport Matsumoto wase Fuyu have been crossed with A4 giving progeny with the same distribution of fruit maturation. If Matsumoto wase Fuyu was a solid mutation (or present in the L2 layer) then the progeny from the cross with A4 would have had a distribution of fruit maturation which tended to be earlier than the Fuyu cross. The very early ripening Fuyu bud-sport Uenishi wase has probably arisen from layer substitution of Matsumoto wase Fuyu (Figure 1).

Figure 1:
Bud Mutation in Persimmon

A similar trend in bud-sports has also occurred in Hiratanenashi. Many cultivars of persimmon have produce early ripening bud-sports suggesting this is an easily mutated single gene mutation. Dwarf and large fruited mutations have also occurred in a number of cultivars.

Occasionally in New Zealand orchards sectorial bud mutations can be seen on fruits as a sector of coloured skin. These tend to be found in the packhouse during grading. One of these fruit was found in our research block. The shoot on which this fruit was found was introduced into tissue culture. Variant shoots and normal shoots were isolated from the shoot. If growers find similar fruits in the orchard the shoot which produced the sectored fruit should be labelled and retained. The recent advances in tissue culture techniques developed at Ruakura could be used to recover this type of mutation.

Conclusion
In New Zealand the early ripening bud mutations of Fuyu and Hiratanenashi could improve the adaptation of persimmon to the New Zealand environment. Currently Fuyu ripens in late autumn. This can expose the fruit to high rainfall, frosts and low heat units during the harvest period. Early ripening selections which ripen in late summer would have a lower risk of ripening under adverse conditions. Low vigour or spur types could be suited to high density orchard systems.

Table 1:
Characteristics of Fuyu Bud Sports

Name	Characteristics
Matsumoto wase:	The first early ripening bud mutation of Fuyu identified. The fruit matures 14 days before Fuyu. Trees have moderate vigour and are prone to over cropping. The fruit is smaller than Fuyu and is sensitive to the green blotch disorder.
Moritani:	An extremely early ripening bud mutation of Fuyu recently patented in Japan. The fruit is larger (300g) and matures 28 days before Fuyu Fruit sugar content is 3-4 Brix higher. The fruit is similar to Matsumoto wase Fuyu with small fruit size and has sensitivity to the green blotch disorder.
Sunami:	A large fruited bud mutation of Fuyu recently patented in Japan. The fruit matures 10 days before Fuyu. Sunami has better flavour and texture than Matsumoto wase Fuyu.
Uenishi wase:	A recent bud mutation of Matsumoto wase Fuyu that has originated in the Nara Prefecture. The fruit matures 21 days before Fuyu and 7 days before Matsumoto wase Fuyu. The fruit is similar to Matsumoto wase Fuyu with small fruit size and has sensitivity to the green blotch disorder.
Kanagawa wase:	An unnamed early Fuyu bud sport that has been selected in the Kanagawa Prefecture. Its cultivation is restricted to a few orchards in the locality where it originated. The fruit matures 14 days before Fuyu, fruit size is large (300g) and the incidence of calyx separation is low. The fruit is superior to Matsumoto wase Fuyu. The tree is high yielding (25 t/ha) and the leaves have a dark green appearance.
Isahaya:	A large fruited (450g) selection of Fuyu from Nagasaki. This selection was patented in 1986 and information about its performance is limited. At Akitsu the tree was prone to late fruit drop and fruit texture was not as good as Fuyu. Fruit sugar content may be 2o Brix lower than Fuyu.

Table 2:
Characteristics of Hiratanenashi bud sports

Name	Characteristics
Tone wase:	Similar to Hiratanenashi but the fruit matures 10 days earlier. More sensitive to green blotch than Hiratanenashi. Within 6 years of patenting this cultivar now occupies 30% of the Hiratanenashi production area. Ideal for vinyl house culture as good fruit skin colour can develop under warm temperature conditions.
Sado wase:	Similar to Tone wase but it originated on Sado Island. The fruit matures at the same time as Tone wase in the Niigata Prefecture. Under warmer conditions in Nara prefecture Sado wase matures 7 days earlier than Tone wase. Tree size is larger than Tone wase.
Ishibashi wase:	This selection was recently found in the Yamamaka Prefecture and is the earliest ripening Hiratanenashi bud sport. Fruit reach maturity 24 days earlier than Hiratanenashi. Fruit size tends to be very small.
Sugita wase:	Fruit matures 7 days earlier than Hiratanenashi. The fruit is slightly larger than Hiratanenashi. The shoots are large and coarse, leaves are thicker than normal and the flower pedicel is long. This selection is not popular due to high fruit drop, hard textured flesh, low flavour and sugar. Astringency is more difficult to remove than Tone wase.
Shimoda wase:	Fruit matures 5 days earlier than Hiratanenashi. The fruit has an undesirable flattened appearance.
Kimura:	This selection is similar to Hiratanenashi in all characteristics except that fruit are 1.5o brix higher in sugar.
O'Tane nashi:	This selection produces larger fruit (300g) than Hiratanenashi (180g). The shoots have a distinctive curved and flattened appearance. Yield potential is similar to Hiratanenashi. O'Tane nashi has recently been patented. Recent studies on the use of O'Tane nashi as an inter-stock for Tone wase have indicated that fruit maturity can be advanced by 3 days and fruit size increased by 20%.
Sado O'Tane:	A similar selection to O'Tane nashi which originated on Sado Island. Fruit drop tends to be high and the flesh can contain a large number of brown spots.
Ko Sado kaki:	This is a dwarf selection of Hiratanenashi. Frequent bud reversion limits its use.
Tokushima spur:	This is a dwarf selection with a distinctive spur growth habit. The leaves have a wavy margin. Bud reversion is common.

Photo 1:[37k]
Sectorial chimeral on a Fuyu fruit

Photo 2:[55k]
Tone wase, an early ripening bud mutation of Hiratanenashi

Source:
The Orchardist of New Zealand 66(3):44-46. (1993)