为解决‘京白梨’品质退化的问题，以北京地区‘京白梨’结果树为试材，比较不同秋子梨授粉品种、坐果序位和立地条件（丘陵和平地果园）对‘京白梨’果形和果重的影响。结果表明，利用‘子母梨’、‘山梨’、‘鸭广梨’、‘金香水’和‘寒红’分别给‘京白梨’授粉，‘山梨’、‘寒红’授粉效果最佳，获得的‘京白梨’果重分别为113.60、110.80 g，果形指数均为0.82；3~5序位坐果率高、果重大，优于1~2序位和6~9序位坐果；山地丘陵果园‘京白梨’果重100.77 g、果形指数0.82，而平地果园果重125.08 g、果形指数0.87，果形指数受立地条件影响。综上所述，为保证‘京白梨’果形的典型性，可配置‘山梨’和‘寒红’为授粉品种，疏果保留3~5序位，并在冷凉山区环境种植。

【目的】以3种栽培类型的蓝莓品种‘奥尼尔’(Vaccinium corymbosum ‘O’Neal’)、‘红粉佳人’(V. ashei ‘Pink lemonade’)及‘博尼塔’(V. ashei ‘Bonita’)为父本,与3种倍性的蓝莓配置杂交组合,比较授粉后24个杂交组合坐果率及果实感官品质性状差异,为蓝莓杂交育种的亲本选择和栽培实践中授粉树选配提供参考。【方法】以各杂交组合果实为试材、母本品种自然授粉为对照(CK),测定果实外观指标、主要糖类、抗氧化物质、挥发性物质含量等果实感官品质指标。【结果】3个父本与兔眼品种‘沃农’(‘Vernon’)‘布莱特蓝’(‘Briteblue’)杂交亲和性较低,用‘奥尼尔’和‘博尼塔’对高丛蓝莓品种授粉后均有较高的坐果率,用‘奥尼尔’花粉授粉后的‘天后’(‘Primadonna’)果实单果质量降低而硬度显著提高,用‘博尼塔’花粉授粉‘天后’的果实果形指数明显提高。观察杂交种子发现,‘红粉佳人’与南高丛品种杂交坐果率较高且果实无籽,3个父本与兔眼品种‘顶峰’(‘Climax’)杂交果实也均无籽。与自然授粉亲本相比,用‘奥尼尔’和‘博尼塔’授粉显著提高高丛品种果实的糖类物质含量,尤以‘博尼塔’授粉‘温莎’(‘Windsor’)和‘天后’果实固酸比极高。芳香物质检测分析发现,各杂交组合中共检测出59种挥发性物质,主要共有物质为芳樟醇、石竹素和反-2-己烯醛。‘夏普蓝’(‘Sharpblue’)经‘博尼塔’和‘奥尼尔’授粉后果实中芳樟醇含量均显著提高,而‘天后’仅经‘奥尼尔’授粉后芳樟醇含量显著提高,且用‘奥尼尔’授粉的‘天后’和‘夏普蓝’果实反-2-己烯醛含量显著高于自然授粉果实。兔眼品种‘顶峰’经‘红粉佳人’授粉后挥发性物质种类增加明显且以烯类物质较多。总酚和花色苷含量在不同倍性授粉组合中变化趋势相似,以‘奥尼尔’为父本的‘顶峰’果实总酚和VC含量最高,自然授粉的‘天后’和‘顶峰’果实花色苷含量较高。【结论】不同倍性蓝莓杂交具一定亲和性,兔眼衍生品种‘红粉佳人’与南高丛品种杂交可获得无籽果实,兔眼品种‘博尼塔’与高丛品种杂交果实固酸比提高作用显著,南高丛‘奥尼尔’与兔眼‘顶峰’杂交不仅产生无籽果实且促进了抗氧化物质积累。

Nuclear DNA flow cytometry was used to differentiate ploidy level and determine nuclear DNA content in Rubus. Nuclei suspensions were prepared from leaf discs of young leaves following published protocols with modifications. DNA was stained with propidium iodide. Measurement of fluorescence of 40 genotypes, whose published ploidy ranged from diploid to dodecaploid, indicated that fluorescence increased with an increase in chromosome number. Ploidy level accounted for 99% of the variation in fluorescence intensity (r2 = 0.99) and variation among ploidy levels was much higher than within ploidy levels. This protocol was used successfully for genotypes representing eight different Rubus subgenera. Rubus ursinus Cham. and Schldl., a native blackberry species in the Pacific Northwest, which has been reported to have 6x, 8x, 9x, 10x, 11x, and 12x forms, was extensively tested. Genotypes of R. ursinus were predominantly 12x, but 6x, 7x, 8x, 9x, 11x, and 13x forms were found as well. Attempts to confirm the 13x estimates with manual counts were unsuccessful. Ploidy level of 103 genotypes in the USDA-ARS breeding program was determined by flow cytometry. Flow cytometry confirmed that genotypes from crosses among 7x and 4x parents had chromosome numbers that must be the result of nonreduced gametes. This technique was effective in differentiating chromosome numbers differing by 1x, but was not able to differentiate aneuploids. Nuclear DNA contents of 21 diploid Rubus species from five subgenera were determined by flow cytometry. Idaeobatus, Chamaebatus, and Anaplobatus were significantly lower in DNA content than those of Rubus and Cylactis. In the Rubus subgenus, R. hispidus and R. canadensis had the lowest DNA content and R. sanctus had the highest DNA content, 0.59 and 0.75 pg, respectively. Idaeobatus had greater variation in DNA content among diploid species than the Rubus subgenus, with the highest being from R. ellipticus (0.69 pg) and lowest from R. illecebrosus (0.47 pg).

为寻找湖北省香榧生产中适合的花粉,开展香榧花粉直感现象研究,探讨湖北榧树花粉的利用价值。试验以香榧结果母树为母本(A),选用浙江嵊州木榧(B)和湖北通山榧树(C)作为父本进行人工授粉,检测比较2种父本来源组合的果实形态指标、经济指标和养分含量。结果表明,嵊州花粉和通山花粉对榧籽大小和榧核形状表现出花粉直感现象;对榧籽单籽重、单核重和出仁率等经济指标,对榧籽含油量、蛋白质、维生素E和脂肪酸等主要营养成分没有明显的花粉直感现象。说明通山花粉可以在香榧生产中应用,通山榧树雄株资源有开发利用价值。

为了分析不同类型柚类种质资源果实品质特点，建立柚类果实品质的综合评价体系，本研究测定了51份不同类型柚类果实的单果质量、果实纵径、横径、果皮厚度、可食率、可溶性固形物、可滴定酸等品质指标，并利用相关性分析和主成分分析法对果实品质进行综合评价。结果表明：果实纵径为64.00~191.00 mm，横径为76.00~170.90 mm，果形指数为0.82~1.35，单果质量为220.00~1750.00 g，果皮质量为50.00~996.00 g，可食率为19%~81%，果皮厚度为4.00~39.67 mm，嚢瓣数为10~20，可溶性固形物为4.50%~10.90%，可滴定酸为0.13%~2.96%，固酸比为2.70~41.70，种子数为0~224粒，可见，云南省河口柚子种质资源的表型多样性丰富。采用Pearson法对其主要品质特性进行相关性分析发现，纵径与果形指数、单果质量呈显著正相关，横径与单果质量、果皮质量呈极显著正相关，可食率与果皮厚度、可滴定酸与固酸比呈显著负相关；聚类分析得出，这些柚类种质大致分为4类，每个类群在果实外观和内在品质方面均存在较大差异。利用主成分分析法将13个性状分成4个主成分因子：第1主成分贡献率为31.614%，以果实形态为主，纵径、横径、单果质量、果皮质量贡献较大；第2主成分贡献率为16.842%，可食率、可溶性固形物、嚢瓣数贡献较大；第3主成分贡献率为15.397%，可滴定酸贡献较大；第4主成分贡献率为14.686%，种子数量等贡献较大。经过果实品质分析与综合评价，云青1号、青皮红心柚、黄金蜜柚、琯溪红肉蜜柚、东试早柚和晚白柚为综合品质优异的的种质资源，可优选作为云南河口主栽品种或育种亲本材料。