新疆野生甜瓜形态学观察及其与不同变种杂交亲和性研究

Morphological Observation on Xinjiang Wild Muskmelons and Study on Cross Compatibility between Them and Different Varieties in Cucumis melo L.

【目的】通过形态学观察鉴定与种内不同变种间杂交亲和性研究,为明确新疆野生甜瓜分类地位和扩大甜瓜栽培品种遗传基础提供支撑。【方法】观察比较两份新疆野生甜瓜和地方品种叶片、茎、花及果实等28个形态学性状,利用苗期接种技术鉴定新疆野生甜瓜对蔓枯病和白粉病的抗病性。同时,以亚种ssp.agrestis内var.agrestis、var.conomon、var.dudaim、var.chito和var.momordica等5个变种,亚种ssp.melo内var.cantalupensis、var.inodorus和var.flexuosus等3个变种为试材,通过人工授粉杂交后坐果率和结籽率的观察记录,分析新疆野生甜瓜与种内的8个变种间的杂交亲和性。【结果】哈密野甜瓜绝大多数性状与栽培品种对照差异明显,而吐鲁番野甜瓜大部分性状与对照接近。苗期人工接种甜瓜蔓枯病和白粉病菌后,哈密野甜瓜高抗蔓枯病、不抗白粉病,吐鲁番野甜瓜和对照易感或高感蔓枯病和白粉病。人工授粉杂交后,新疆野生甜瓜与2个亚种的8个变种之间未发现不亲和不稔现象;野生甜瓜与8个变种杂交果实的结籽率正反交间有差异,以野生甜瓜为母本时的结籽率高于父本时的;此外,哈密野甜瓜与亚种ssp.agrestis和ssp.melo杂交的平均结籽率分别为79.3%和83.4%,吐鲁番野甜瓜与两个亚种杂交的平均结籽率分别为76.1%和79.4%,野生甜瓜与两个亚种杂交的平均结籽率相近。【结论】新疆野生甜瓜哈密野甜瓜的形态性状与亚种ssp.agrestis内野生变种的性状相近,而吐鲁番野甜瓜的形态性状接近于地方栽培品种。经苗期接种鉴定,哈密野甜瓜对甜瓜蔓枯病表现高抗。新疆野生甜瓜与甜瓜两个亚种ssp.agrestis和ssp.melo可正常杂交且杂种后代可育,应当被划分在C.melo.内。

【Objective】Through morphological observation,identification and cross compatibility between wild muskmelon and varieties in Cucumis melo L. this project aims to provide a support for the classification of wild muskmelons in Xinjiang and the genetic base of melon cultivars.【Method】Twenty-eight traits of leaf,stem,flower and fruit of Xinjiang wild melon were observed and compared with local landraces,and the disease resistance of wild melon in Xinjiang to 2 fungi diseases： gummy stem blight（ GSB） and powdery mildew was identified by inoculation technique at the seedling stage. Meanwhile,cross compatibility between Xinjiang wild melon and 8 varieties,in which 5 were included in ssp. agrestis,var. agrestis,var. conomon,var. dudaim,var. chito and var. momordica,and 3 were included in ssp. melo,var. cantalupensis,var. inodorus and var. flexuosus were analyzed,by the way of recording on fruit-setting and seed-setting rate of combinations after artificial pollination.【Result】Results obtained showed that most morphological traits of ＇Hami wild＇were distinct from the local cultivated control,but traits of ＇Turpan wild＇ were similar to the control. ＇Hami wild＇ was highly resistant to GSB but susceptible to PM,while ＇Turpan wild＇ was susceptible or highly susceptible to GSB and PM after inoculation at seedling stage. Infertility of hybrids and incompatibility were not observed among any combinations between Xinjiang wild melon and 8 varieties. Except var. agrestis and chito,the seed-setting rate between reciprocal crosses was found differentially among combinations between Xinjiang wild melon and 8 varieties,which higher seed-setting rate was detected when Xinjiang wild melon was used as female parent. Furthermore,the seed-setting rate between ＇Hami wild＇ and 2 subspecies,ssp. agrestis and ssp.melo,were 79. 3% and 83. 4%,respectively; and the seed-setting rate between ＇Turpan wild＇ and 2 subspecies were 76. 1% and 79. 4%,respectively,which indicated that seed-setting rate exhibited small differences between combinations of Xinjiang wild melon with ssp. agrestis and with ssp. melo. 【Conclusion】Morphological traits observed in ＇Hami wild＇ looked like that of feral or weedy melon in ssp. agrestis,however,＇Turpan wild＇ showed affinities with local landraces. ＇Hami wild＇ was highly resistant to GSB after screening in seedlings. Xinjiang wild melon could be classified into C. melo,because of fertility of hybrids and compatibility were detected between wild melon and 2 subspecies,ssp. agrestis,ssp. melo.