บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Prevention of bud and floret abscission in Cestrum cut flowers depends on the mode of transport and metabolism of synthetic auxins.

Abebie B., Goren R., Huberman M., Meir S., Philosoph-Hadas S., Riov J.

5th International Postharvest Symposium . Volume of Abstract . Verona, Italy 6-11 June 2004. page 34

2004

บทคัดย่อ

Prevention of bud and floret abscission in Cestrum cut flowers depends on the mode of transport and metabolism of synthetic auxins.    Red Cestrum (Cestrum elegans Schlecht.) cut flowers are considered as a new export crop from Israel, although they exhibit both bud and floret abscission during shipment.However, pulsing Cestrum cut flowers for 4 h at 20 °C + 16 h at 4 °C with 2,4-dichlorophenoxyacetic acid (2,4-D) combined with sliver thiosulfate (STS) significantly reduced abscission, while 1-naphthaleneacetic acid (NAA) failed to do so.

Contrary to its inhibitory effect o­n floret abscission, 2,4-D induced higher level of ethylene evolution compared to NAA.The data suggest that 2,4-D moved acropetally in a significant amount, sufficient to reduce floret abscission, while NAA did not.These surprising results lead us to study the mode of transport of 2,4-D and NAA in stem sections and intact shoots.In stem sections, transport of NAA did not.These surprising results lead us to study the mode of transport of 2,4-D and NAA in stem sections and intact shoots.In stem sections, transport of NAA was polar with a velocity of 5.92 mm per h.Although the major 2,4-D transport was also polar, it contains a significant non-polar transport component: a fast transport during the first 15 minutes both in the acropetal and basipetal directions, followed by a progressively increased basipetal and decreased acropetal transport.During the transport period of 3 to 11 h, 2,4-D moved at a rate of 1.87 mm per h in the basipetal direction.

Studies with intact flowering shoots also showed a significant acropetal transport and accumulation of 2,4-D in the upper parts of the stem, leave and florets, while NAA mainly accumlated in the lower parts of the stem.In addition, NAA was metabolized in florets and leaves faster and more than 2,4-D.This suggests that like other abscission systems, the interaction between ethylene and free auxin level, in the tissues, control abscission of buds and florets in Cestrum.