; Mostafa et al., 2010 ). In the horticultural and forestry practice, the plants are propagated mainly by seed. However, there is rather confusing information concerning the ecophysiology of Arbutus sp. seed germination. Mesléard and Lepart (1991
. The degree to which a plant is able to accomplish this goal is also one of the main factors determining the invasive potential of a species ( Dozier, 1999 ). Seed production and seed germination have been the primary criteria in evaluating exotic
. dasycalyx seed germination rates increased significantly after sulfuric acid scarification. Wang et al. (2012) also found that a 15-min sulfuric acid scarification treatment increased the seed germination rate and germination energy of Hibiscus hamabo
Germination was greater for seeds scarified manually or with 15% NaOCl than for those scarified with concentrated H2SO4. Fifteen percent NaOCl for 18 hr scarified the seed endocarp and negated the need for stratification. Germination of 85% was attained after 8 weeks incubation in the light at alternating 15°/30°C. This percentage compared favourably with 82% germination resulting from manual scarification techniques. Electron microscopy revealed that endocarp degradation was much more extensive after 18 hr in 15% NaOCl than after 4 days in a 1% solution.
Germination rate of pepper (Capsicum annuum L.) seed was reduced and germination became less uniform as temperature was lowered from 25° to 15°C. There was no evidence of a leachable or extractable germination inhibitor being activated or formed during the exposure to low temperature. Auxin and kinetin applications did not alter germination rates, but gibberellins (GA3 and GA4+7) increased germination rates. GA4+7 was slightly more effective than GA3 in stimulating a germination rate increase. AMO 1618 effectively reduced germination rates.
Germination of Myrica pennsylvanicum was increased by exogenous application of kinetin to scarified, cold-stratified seeds. Gibberellic acid (GA3) at 500 and 900 ppm decreased time required for stratification and increased total percentage germination. GA3 was more effective than kinetin for increasing germination.
Blueberry seeds (Vaccinium ashei Reade cv. Tifblue) were aspirated into several terminal velocity (TV) grades in an elutriation column. Different light and temperature environments were used to germinate the seeds. In all tests, germination was best at TV grades 2.23 and 2.45. Seed remaining in the air columns after aspiration did not germinate. Light was necessary for germination.
There are differences among Kalmia species in their requirements for germination: pregermination treatments are effective with 3 of the species. Kalmia hirsuta seeds require a heat-humidity treatment, whereas those of K. latifolia and K. cuneata respond to stratification. Gibberellin (GA) can substitute for stratification. Soaking seed for 24 hr in 100 ppm of GA is sufficient for K. latifolia, where dormancy is partial, but for K. cuneata 1,000 ppm GA is required. The dormancy of fresh K. latifolia seed disappeared following storage for a year or more; seeds remained viable for 9 years. Seed of K. angustifolia, K. polifolia, and K, microphylla germinated well in three weeks at 22°C without pretreatment. Germination of K. angustifolia, K. polifolia, and K. cuneata was good between 18 and 30°C, but K. latifolia was sensitive to temperatures above 26°. Light was required for germination of K. hirsuta, K. angustifolia, K. polifolia, and K. latifolia and is probably a requirement of the other species. This information about germination should facilitate the growing and testing of Kalmia seedlings for ornamental and other purposes.
perpendicular widths [(width1 + width2) ÷ 2]. Growth index rates were calculated by subtracting the initial growth index from the final growth index. Seed germination and viability. Mature fruit were removed from plants in mesh bags and depulped by hand using a
refine the standard seed germination protocol, in vitro seed germination methodology, and vegetative propagation techniques, including in vitro multiplication of cloned plantlets, to facilitate ex situ conservation and development of a new methodology for