南果梨适宜采收成熟度的研究

对南果梨适宜采收期进行了研究。试验结果表明,早期采收果实中可溶性固形物含量较低,果实呼吸代谢旺盛,耐贮性差;晚期采收的果实可溶性固形物含量增加,适合鲜食,不适合长期贮藏;南果梨较为适宜采收期应为9月9日前后。果实硬度、可溶性固形物含量、种子转色指数可作为确定采收成熟度的指标。     

“气候好”农产品贵德软梨评价指标研究

为了提高贵德梨果的栽培经济效益,本研究选取贵德名优农产品中取得地理标志的产品贵德软梨,开展了“气候好”农产品气候品质认定,确定了评价指标。采取综合认证方法,考虑影响农产品生长的生态适应性、当年的气候条件、管理水平和当年水果品质情况所占的比重,赋予不同的权重。并对各项分析打分,得到综合分数来确定。选取2020年贵德县园艺场的软梨进行了认定指标评价,结果表明2020年贵德县园艺场光热资源丰富、水分条件适宜、光热水匹配良好、气候优势明显,有利于优质软梨生产,2020年出产的贵德软梨气候品质等级为“特优”。     

氮磷钾配施对苦瓜产量和品质的影响

采用田间试验的方法研究了氮磷钾配施对苦瓜产量和品质的影响。结果表明,氮肥、磷肥和钾肥以及适宜配合施用可显著提高苦瓜的产量。氮肥可提高苦瓜粗蛋白和氨基酸的含量,降低苦瓜维生素C和糖分含量,磷肥可提高粗蛋白和糖分含量,钾肥可以提高苦瓜维生素C、糖分和氨基酸含量,减缓施氮不合理带来的负面影响。充足的钾素供应和适宜的氮磷钾配比是保证苦瓜产量和品质的关键。     

梨树大棚栽培棚内外温湿度环境变化规律和物候期研究

为梨大棚栽培技术的制定提供参考依据,对梨树大棚栽培棚内外空气温度、空气相对湿度、土壤温度以及梨树物候期的变化特点进行比较。结果显示：（1）随季节的变化,气温和地温均呈逐渐上升趋势, 6月之前棚内气温、相对湿度和地温均高于露地,且昼夜温差大于露地,6月起棚内外温度差异不显著。（2）棚内栽培‘翠冠’和‘黄冠’梨萌芽早,但落叶晚,整个营养生长期分别为242天和231天,分别比露地长27天和37天。（3）大棚栽培的‘翠冠’和‘黄冠’梨开花期比露地皆提早18天,且花期比露地长2天。（4）棚内栽培条件下,‘翠冠’和‘黄冠’梨采收期分别提早13天和14天,而果实发育期比露地分别长5天和4天。研究结果表明,大棚条件下温湿度高,开花期提早,果实成熟期提前,南京地区可进行梨保护地栽培。     

抑制剂对鲜榨蜜梨汁多酚氧化酶活性的影响

多酚氧化酶(PPO)是酶促褐变的关键酶,以鲜榨蜜梨汁为原料,以邻苯二酚为底物,采用分光光度法测定多酚氧化酶活性,研究氯化钠、柠檬酸、L-半胱氨酸、抗坏血酸和异抗坏血酸5种不同抑制剂对鲜榨蜜梨汁中的多酚氧化酶活性的影响。结果表明,这5种酶抑制剂均能在一定程度上抑制鲜榨蜜梨汁PPO活性,随着其浓度的升高,抑制效应逐渐增强。氯化钠、柠檬酸、L-半胱氨酸、抗坏血酸、异抗坏血酸抑制鲜榨梨汁PPO活性的最佳浓度分别为0.6,0.5 mol/L和2.0,2.0,0.5 mmol/L。     

低温对库尔勒香梨不同部位抗氧化酶活性的影响

为了解香梨不同部位的抗寒能力与抗氧酶活性是否具有相关性,以库尔勒香梨为材料,测定不同部位越冬过程中抗氧化酶活性的变化。结果表明,库尔勒香梨不同部位在越冬过程中体内SOD,POD,CAT活性有明显的变化。SOD活性变化总体规律都随温度的上升而降低,不同部位之间的SOD活性没有明显差异;各部位的SOD活性不同月份之间有明显的差异,在最为寒冷的1月份达到最高值,其中休眠芽的活性为最高。POD活性随温度的逐渐升高而上升,3月份达到最高,其中主干阳面和阴面的POD活性高于其他部位。阳面和阴面CAT活性随温度的提高而回升,2月份最低,休眠芽和枝条CAT活性均逐渐下降。     

不同产地香菇氨基酸组成及营养价值评价

为比较不同产地香菇的氨基酸组成差异,使用氨基酸自动分析仪快速检测了5种不同产地香菇的氨基酸组成,采用氨基酸比值系数法对其氨基酸进行营养价值评价。结果表明,不同产地香菇的氨基酸含量不同,总氨基酸含量在(14.39～18.71) g/100 g;必需氨基酸含量相差较大,其范围为(4.68～6.33) g/100 g,必需氨基酸占总氨基酸(EAA/TAA)的平均值为34%,必需氨基酸占非必需氨基酸(EAA/NEAA)的平均值为51%。在5种香菇样品中,亮氨酸的比值系数(RC)最小,为第一限制性氨基酸,氨基酸比值系数分(SRC)平均值为87.846。四川通江(Q5)香菇的SRC值最高,且各必需氨基酸的RC值与1接近,与模式氨基酸最接近,因此从氨基酸含量及必需氨基酸所占比例来讲,四川通江(Q5)香菇的品质最佳,可作为香菇蛋白产品开发与利用的理想资源。     

A molecular technique for selection of self-compatible varieties of Japanese pear (Pyrus pyrifolia Nakai)

The pear cultivar ‘Osa-Nijisseiki’ (S₂S^sm ₄; sm = stylar-part mutant) has been used as a parent to breed self-compatible cultivars that produce excellent fruits. However, determination of the self-compatibility of ‘Osa-Nijisseiki’ offspring requires a lot of time, 6 years or more, by conventional cross breeding. We have designed a rapid reliable method for the identification of self-compatible varieties of ‘Osa-Nijisseiki’ offspring based on the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) with S-allele specific restriction endonucleases. By using this method, 8 self-compatible varieties were selected among 16 selections resulting from a cross between the self-compatible cultivar ‘Osa-Nijisseiki’ (S₂S^sm ₄) and the self-incompatible cultivars ‘Niitaka’ (S₃S₉), ‘Whasan’ (S₃S₅), ‘Chuwhangbae’ (S₄S₆). The S-genotypes of 16 ‘Osa-Nijisseiki’ offsprings were also determined. This revised version was published online in August 2006 with corrections to the Cover Date.     

Polyacrylamide gel electrophoresis of S-RNase fragments for identification of S-genotypes of Japanese pear (Pyrus pyrifolia)

Japanese pear (Pyrus pyrifolia) exhibits gametophytic self-incompatibility (GSI) controlled by a complex and multiallelic S locus. The pistil-part product of the S locus is the polymorphic ribonuclease, S-RNase. Information on S-genotypes is important for the production and breeding of Japanese pears. Molecular analyses of S-genotypes of Japanese pear have been conducted with the CAPS (cleaved amplified polymorphic sequence) system; PCR amplification of S-RNase fragments by a common primer pair followed by digestion with restriction enzymes each of which cleaves a specific S haplotype. Here, we show that the separation of S-RNase fragments by polyacrylamide gel electrophoresis (PAGE) distinguishes four out of nine S haplotypes of Japanese pear without restriction digestion. S³-, S⁵-, S⁶- and S⁸-RNases were identified as distinct bands by PAGE. S³- and S⁵-RNases were separated by PAGE despite their identical fragment sizes. Using this system, three Japanese pear lines with unknown S-genotypes were analyzed. The newly determined S-genotypes of the lines were confirmed by CAPS analysis.     

不同气体配比对丰水梨采后贮藏效果的影响

采用不同的气体配比(O2∶CO2)处理丰水梨,探讨(0±0.5)℃、相对湿度95%条件下贮藏140 d期间果实品质的变化规律。结果表明,丰水梨果实的可滴定酸含量及果实硬度在贮藏过程中呈逐渐下降的趋势,其中2%O2+1%CO2和5%O2+5%CO2两个处理的果实硬度和可滴定酸含量显著低于对照(20.9%O2+0.03%CO2)(P0.05),5%O2+1%CO2、5%O2+3%CO2、10%O2+1%CO2和10%O2+3%CO2处理组高于对照;VC含量与可溶性固形物含量(SSC)的变化趋势均为先升后降,其中5%O2+1%CO2处理出现峰值最迟且峰值较高;各组丰水梨果实的失重率变化不明显。本试验中以5%O2+1%CO2处理的丰水梨果实贮藏品质最佳。