钴-60辐照芒果果实的防腐保鲜效应

Effects of Gamma Radiation on Rotting Fungi and Storage Li fe of Mangos

应用６０Ｃｏγ射线辐照，结合５２℃－５５℃热水和热化学等，处理海南省两个地区的白象牙、吕宋、青皮、椰香、白玉和秋芒果实。经不同贮藏时间的病情和成熟度变化调查，用国际标准化软件ＳＡＳ分析，结果表明辐照剂量为２５０Ｇｙ结合各种预处理，炭疽病的平均病情指数比未处理果实极显著减低，其防效为５０％左右。５５０（或９００）Ｇｙ比不辐照果实的蒂腐病平均病情指数亦极显著减少，防效为１７．０７％～３２．８４％。辐照和热水或热化学等结合处理的效果极显著高于单独辐照效果，对炭疽病防效为４６．７９％～９１．３６％，蒂腐病防效为５０．８６％～７４．３２％。２５０Ｇｙ辐照剂量可减缓后熟变化速度，延长贮藏期１～８ｄ。剂量超过５００Ｇｙ不仅未减慢后熟速度，还可造成白象牙和吕宋芒果皮出现褐色小斑。５００μｇ／ｍＬ施保克造成白象牙和白玉芒果皮从紫褐色到黑色的伤害。

Mangos were harvested from six cultivars namely，Nang Klangwan，Carabao，Okro-ng，Dashehari，Baiyu and Neelum at two locations in Hainan. The Mangos were treated withgamma radiation combined with hot water and hot fungicides at 52～55℃. Incidence of diseaseand ripening rate during storage were investigated and statistically analyzed by using an interna-tional accepted software SAS．Results showed that[60]Co irradiation in combination with variouspretreatments reduced significantly anthracnose（Colletotrichum gloeosporioides）as comparedwith the nontreated control and gave a controlling effect of about 50％. Pretreatment plus irradi-ation at 550 or 900 Gy Gyredued stem end rot（Diplodia natalensis）evidently as compared withthe nonirradiation，and had a cotrolling effect of 17 07％～32．84% .Gamma radiaton cornbinedwith hot water or hot fungicides showed better effcet than irradiation alone. The effect of controlfor anthracnose and stem end rot was at 46．79～91．36％ and 50．86～74．32%，respectively.Treatment by 250Gy gamma rays retarded ripening rate and extended storage life from 1 to 8days. But for Nang Klangwan and Carabao mangoes，the treatment not only had no retardationeffect，but also caused unacceptable surface damage（i．e. lenticel browning spot）at doses ex-ceeding 500Gy. The scald-like peel injury（from brown to black）of cv. Nang Klangwan andBaiyu mangos was caused by hot prochloraz of 500μg/mL.