Effect of ultrasonics on the germination of wild rice (<i>Zizania aquatica</i>)

Halstead, E.H.; Vicario, B. T.

doi:10.1139/b69-237

Cited by 10 publications

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“…Using wet seed stored 128 days, Simpson increased the germination percentage four to I O-f old by a single puncture in the scutellar region of the seed coat of dehulled seeds with a dissecting needle, a response suggestive of seed coat impermeability as a dormancy factor. Further support for seed coat impermeability as a factor of dormancy was presented by Halstead and Vicario (1969) who reported no germination for untreated seeds removed from l to 3 C wet storage 90 days after harvest. Treating seeds with ultrasonic vibrations at 70 kcjs for lO min resulted in 74% germination.…”

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confidence: 91%

Seed Dormancy Mechanisms in Wild Rice (Zizania aquatica)¹

Cardwell¹,

Oelke

Elliott

1978

Agronomy Journal

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Freshly harvested seeds of wild rice (Zizania aquatica L.) require 3 to 5 months of moist storage at 1 to 3 to induce germination. Dormancy lasting more than 1 year has been noted. These periods of dormancy pose problems to plant breeders desiring multiple generations per year and to growers desiring to change varieties in establish fields. The purpose of this research was to determine the role of the pericarp in seed dormancy, the existence of germination inhibitors, and the influence of gibberellin and kinetin on germination of dormant wild rice seeds. The pericarp of seeds harvested the previous day was scraped off, punctured, or cut at several locations on the seed. Germination occurred only when the treatments were made directly over or very near the embryo, indicating mechanical resistance by the pericarp. Soil collected from fields 1 and 2 years out of production was screened for seed. The pericarps of nongerminating seeds were randomly punctured, increasing germination 33 and 79% respectively. This suggests an impermeable pericarp. Freshly harvested seeds from which the pericarp was either scraped or not scraped were germinated in aqueous extracts of the pericarp, and hulls (lemma and palea) from freshly harvested seeds. Aqueous extracts of the pericarp reduced germination 77% while aqueous extracts of the hulls reduced germination 84%, compared to scraped seed germinated in water. Aqueous extracts of the hulls from seeds stored for 1 year had little influence on germination when used as germination media for freshly harvested scraped seeds. The hulls were removed from some freshly harvested seeds and not from others before storing for 1, 2, and 4 weeks in water at 1.5 C. Seedling survival after 30 days was significantly reduced when lemmas and paleas were left on the seeds 1 or 2 weeks during storage in water at 1.5 C. These experiments support the contention of growth regulators in the hulls of freshly harvested seed. All combinations of 0, 0.01, 0.1, 1, and 5μM solutions of gibberellic acid (GA3) and kinetin were applied to germinated dehulled, punctured seeds. Before seeds were dehulled and punctured, they were stored in plastic containers at 1.5 C for 90 days. Germination increased from 36 to 51% as GA3 concentrations increased. Kinetin alone had little influence on germination except in combination with GA3. Less etiolated seedlings were obtained when kinetin was included in GA3 treatments. The addition of 5μM GA3 + 1μM kinetin increased germination of freshly harvested, scraped seeds from 29 to 76%. Wild rice appears to have multiple mechanisms of seed dormancy. The seed pericarp exhibits mechanical resistance and impermeability. Water soluble germination inhibitors appear to be present in hulls and pericarp, and gibberellic acid concentrations are low in freshly harvested seed. Freshly harvested seed can be germinated by dehulling and scraping, permitting multiple generations per year in breeding programs. Persistence of dormant seeds in fields will present problems in introducing new var...

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confidence: 91%

Seed Dormancy Mechanisms in Wild Rice (Zizania aquatica)¹

Cardwell¹,

Oelke

Elliott

1978

Agronomy Journal

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“…Often, wild rice seeds must be stored under water (after ripened) at near freezing temperatures for periods up to 6 months before any reasonable germination percentage is obtained. 18 Even after long periods of controlled storage, germination percentage can be low. Seed coat impermeability and kernel immaturity have been suggested as possible causes for low percentage germination.…”

Section: Germination Of Seedsmentioning

confidence: 99%

“…Seed coat impermeability and kernel immaturity have been suggested as possible causes for low percentage germination. 18 Wild rice sown in the lakes of northern Saskatchewan has been observed to lie dormant in the lake bottom for 1 or more years with germination taking place when conditions were right. 18 Simpson 43 reported a dormancy period of at least 96 days when the seed was after-ripened at 1 to 3°C, with dormancy being lost after 182 days.…”

Section: Germination Of Seedsmentioning

confidence: 99%

“…18 Wild rice sown in the lakes of northern Saskatchewan has been observed to lie dormant in the lake bottom for 1 or more years with germination taking place when conditions were right. 18 Simpson 43 reported a dormancy period of at least 96 days when the seed was after-ripened at 1 to 3°C, with dormancy being lost after 182 days. Even after 182 days after-ripening, germinating seeds at 20° C took 143 hr to reach 50% germination.…”

Section: Germination Of Seedsmentioning

confidence: 99%

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Wild rice: The Indian's staple and the white man's delicacy

Lorenz

Lund

1981

C R C Critical Reviews in Food Science and Nutrition

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Wild rice (Zizania aquatica) is an annual aquatic grass which grows in shallow lakes, marshes and in sluggish streams in various parts of the world. The grain of wild rice has been harvested by the Indians of the United States and Canada for many centuries. Explorers entering the territories of the Northern Lake States of America a few centuries ago described wild rice as a spontaneous crop which does not require plowing or sowing providing an abundant harvest of palatable and nourishing grain. Natural propagation assured the Indians of a yearly crop. As time passed, wild rice lost its importance as a staple for the Indian population, but it became a white man's delicacy because of its unique color and flavor characteristics. In the U.S. a commercial wild rice industry developed. The grain is now found on supermarket shelves, but at a rather high price compared to prices for other cereal grains. Today, most of the wild rice in the world is harvested as a cultivated crop from paddies in the state of Minnesota. Smaller amounts are produced in Wisconsin and in southern Canada. Wild rice has some desirable nutritional attributes. Its protein content is relatively high compared to other cereal grains. Wild rice is a good source of the B vitamins, thiamin, riboflavin and niacin and contains common mineral elements in amounts comparable to those in oats, wheat and corn. Wild rice is used as a main meal ingredient in regular or quick cooked form and has numerous possible secondary usages. Because of its good nutritional balance wild rice could help to provide another source of energy and quality protein for the diet of man.

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“…Part of this dormancy is due to an impermeable pericarp. Several attempts have been made to reduce this dormancy period (2,3,5). The use of chemicals to scarify seec_ has not been successful (5).…”

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Mechanical Scarification of Dormant Wild Rice Seed¹

Oelke

Albrecht

1978

Agronomy Journal

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Wild rice (Zizania aquatica L.), which formerly grew only under natural conditions until the early 1960's, is now being grown as a cultivated field crop. A 3 to 6‐month, post‐harvest seed dormancy hinders the continued development of wild rice as a field crop. Part of this dormancy is due to an impermeable pericarp. Scarification with chemicals to increase permeability has not been successful, and scraping the individual seeds to remove the pericarp above the embryo is too time‐consuming. A small rock polisher was evaluated as a scarification device in this study. Three dehulled seed lots, one from greenhouse‐grown plants and two from field‐grown plants with different harvest dates were used. Samples from each were tumbled with dry crushed granite in the polisher for varying times or scraped with a razor blade to remove the pericarp above the embryo. Laboratory and greenhouse gemination were used to measure the resulting release of dormancy. Seed tumbled in the laboratory for 1 hour gave gemination percentages in water of 44 to 60, depending on the seed lot. Scraped seed gave gemination percentages of 65 to 100 for the corresponding seed lots. Tumbling resulted in less seed injury and required less time than scraping seed. Placing tumbled or scraped seed 1.5 cm deep into soil in the greenhouse before flooding gave an average gemination percentage of only 13 compared to 64 when seed was germinated in water. Transplanting seedlings from scarified seeds germinated in water was more successful than direct planting of scarified seed to establish greenhouse stands. Use of the rock polisher significantly accelerated scarifying wild rice seed with a minimum amount of injury. This method may be adapted to other high moisture seed that requires scarification.

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Effect of ultrasonics on the germination of wild rice (Zizania aquatica)

Cited by 10 publications

References 0 publications

Seed Dormancy Mechanisms in Wild Rice (Zizania aquatica)¹

Seed Dormancy Mechanisms in Wild Rice (Zizania aquatica)¹

Wild rice: The Indian's staple and the white man's delicacy

Mechanical Scarification of Dormant Wild Rice Seed¹

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Effect of ultrasonics on the germination of wild rice (Zizania aquatica)

Cited by 10 publications

References 0 publications

Seed Dormancy Mechanisms in Wild Rice (Zizania aquatica)1

Seed Dormancy Mechanisms in Wild Rice (Zizania aquatica)1

Wild rice: The Indian's staple and the white man's delicacy

Mechanical Scarification of Dormant Wild Rice Seed1

Contact Info

Product

Resources

About

Seed Dormancy Mechanisms in Wild Rice (Zizania aquatica)¹

Seed Dormancy Mechanisms in Wild Rice (Zizania aquatica)¹

Mechanical Scarification of Dormant Wild Rice Seed¹