Patent Application
20140115743
This invention relates to a new and distinct variety of mushroom plant of Maitake mushroom, Grifola frondosa (Fr.) S. F. Gray. This new variety named ‘Grifon-7’ cultivated by repeated breeding of Maitake mushrooms having dominant traits, which has thick color of cap surface, white color of back side of cap, excellent cultivability and high yield and ensure presentable stability, reproducibility and uniformity.
Maitake has been artificially cultured and eaten in Japan since long time. The extract of Maitake obtained by hot water extraction contains ingredients that are effective in treatment of cancer because of which there is a great demand of it as a supplement. The demand of fresh Maitake is also increasing. In order to promote the sales of fresh Maitake, it is required that the variety can be cultured easily and the productivity improves. Good external appearance of mushroom, taste, storage characteristics are also important factors to make it appealing to consumers. Although Maitake has been cultured by isolating the strain from the wild variety, however, it has been unsuccessful to artificially control the culture environment that suits the culture of Maitake, because of which it could not be produced in a large scale. Consequently, a new variety called ‘Hokuto NT-100’, which is easy to culture and has improved quality, taste and storability, was developed as a result of repeated improvements through cross-breeding to improve the stability of culture and quality of mushrooms. This variety has been patented in U.S. (U.S. Plant Pat. No. 17,984 P3). However, the under-face of the cap of the Hokuto NT-100 stained easily which made it look less fresh. Thus, the quality of its appearance was identified as a weakness. To overcome this weakness of Hokuto NT-100, cross-breeding was repeatedly conducted as a result of which a new variety named ‘Grifon 120’ that has a white under-face of cap was developed and is pending at the United States Patent and Trademark Office. However, it was pointed out that Grifon 120 has thin color at the top surface of its cap, because of which it looked less fresh. Consequently, new varieties were developed, from which a new variety was selected and named as ‘Grifon-7’ after confirming its stability, reproducibility and uniformity.
The present invention is a new and distinct variety of mushroom characterized particularly by its good qualitative character and appearance, thick color of cap surface, white color of back side of cap, excellent cultivability and high yield, which can be cultivated by collecting and repeated breeding of fungal strains having dominant traits and is exquisite in stability, reproducibility and uniformity when being produced. This novel and distinct variety of mushroom is identified as ‘Grifon-7’.
The history of the Grifon-7 mushroom in terms of improvement period and the like are set forth in the following chronological list of each stage of variety improvement:
The Grifon-7 mushroom has the following characteristics: thick color of cap surface, white color of back side of cap, excellent cultivability and high yield.
(1) Comparison by Dual Culture with Existing Variety
Dislike-touch reaction between Grifon-7 and similar varieties was studied by dual culture.
Grifon-7 and another strain were co-inoculated with an interval of 3 cm by using potato dextrose agar culture medium. Then, the presence/absence of dislike-touch reaction was determined by culturing for 21 days at 25° C.
Grifon-7 (G110537) Present variety
Grifon 120 Varieties similar to the present variety
Hokuto NT-100 Varieties similar to the present variety
Hokuto MY-95 Varieties similar to the present variety
Grifon-7 showed dislike-touch reaction with all other co-cultured varieties
(See Table 1 and
When Grifon-7 was cultured in potato dextrose agar culture medium, hyphae color was white, hyphal density was medium, shape of colony periphery was heterogeneous, thickness was medium, and surface was island.
After inoculating a small piece of Grifon-7 measuring 5 mm diameter in potato dextrose agar culture medium, it was cultured 5-30° C. with 5° C. interval. When the mean mycelial growth rate per day was calculated from the mycelial growth of 10-day culture, it was found that the mean mycelial growth rate was the highest at 26° C.
The mycelial growth rate at 10° C. was fast with 1.31 mm/day, while the growth of similar variety Grifon 120 was slow at 0.56 mm/day. Also, mycelial growth rate at 15° C. was fast at 2.11 mm/day, while the growth of Grifon 120 was medium at 1.68 mm/day. The mycelial growth rate at 30° C. was medium at 2.57 mm/day, while the growth of Grifon 120 was slow at 0.89 mm/day. From the above results, it can be understood that the strain is clearly different from Grifon 120.
(Bag) A polypropylene culture bag (Square-shaped, capacity: 8500-9000 cc, mouth diameter: 200×120 mm, height: approx. 440 mm, air filter present) was used. Altogether 48 bags were used, and cultivation was repeated three times in each in 16 bags.
(Substrate) Sawdust of broadleaf tree, which is mainly beechwood, and corn bran were mixed in the dry-weight ratio of 75:25, and the mixture was adjusted to 60%-62% water content. The substrate was filled at the rate of 2.5 kg per bag, and was sterilized at high pressure.
(Spawn) Sawdust spawn was used. About 25 cc of the spawn was inoculated per bag.
(Culture) Culture was conducted under 20° C.-22° C. temperature, 70-75% humidity and 200-500 lux luminosity, and the cultivar that have primordia formation are shifted to the growing room.
(Growth) The primordia forming bag-culture was shifted to a 17° C.-18° C. temperature, 90-95% humidity and 500-1500 lux luminosity environment to promote the growth of primordia. After the primordia grows up to the extent of touching the filter part, the filter part is taken out and growth of fruit body is promoted. The mushroom is harvested when the pore on the back side of cap about 2-3 mm from the edge.
The characteristics of Grifon-7 cultivated under the conditions mentioned above, and the specific difference in characteristics with the most similar variety Grifon 120 are explained in Table 2 below.
Also, the images of the respective fruit bodies have also been attached. (See
