Postharvest performance of the yellow-fleshed ‘Hort16A’ kiwifruit in relation to fruit maturation

Postharvest performance of fruit is dependent on the maturity or physiological state of the fruit at harvest in conjunction with the postharvest management applied. For yellow-fleshed kiwifruit, the flesh colour is a significant quality attribute, and for ‘Hort16A’, flesh colour has been used for timing harvest. Variability in the postharvest performance of ‘Hort16A’ kiwifruit suggests that flesh colour alone is not as strongly indicative of postharvest performance as soluble solids content (SSC) was found to be for ‘Hayward’ kiwifruit 30 years ago. The postharvest performance of ‘Hort16A’ kiwifruit, assessed as the fruit firmness and chilling injury expression during storage, has been associated with a range of fruit characteristics: flesh colour, SSC, firmness, seed colour, fresh weight, dry matter, starch and soluble carbohydrates measured at harvest throughout maturation. The changing responses of the fruit SSC to temperature, and softening to ethylene, have also been determined. The data illustrate the complex nature of ‘Hort16A’ fruit maturation, even when looking only at simple, easy-to-measure fruit attributes. While a yellow flesh colour is a commercial necessity for ‘Hort16A’ kiwifruit, flesh colour is not a robust indicator of postharvest performance and is not tightly linked to SSC or firmness. Changes in the capacity of fruit to respond to temperature or ethylene are not reflected in on-vine changes. Softening in storage is strongly linked to the softening rate occurring on the vine at the time of harvest. Any association between at-harvest characteristics and chilling susceptibility is less clear, and chilling tolerance appears more associated with the completion of growth and carbohydrate accumulation than with increased soluble solids accumulation rates as in ‘Hayward’. Approaches to extend the understanding of the link between maturation, harvest indices and postharvest performance are discussed.     

Changes in volatile production and sensory quality of kiwifruit during fruit maturation in Actinidia deliciosa ‘Hayward’ and A. chinensis ‘Hort16A’

Although volatiles have been previously studied in kiwifruit (Actinidia spp.), there has been no co-ordinated study of volatile release and softening through the full edible period. In this report, the two most important commercial cultivars A. deliciosa ‘Hayward’ and A. chinensis ‘Hort16A’ were evaluated for volatiles released at different ripening stages corresponding to their typical commercial shelf life, and compared to the sensory quality assessed by a trained taste panel. Gas chromatography–mass spectrometry data indicated that large amounts of straight-chain aldehydes and esters were the dominant volatiles in the two cultivars. In particular, butanoates, the main fruity esters in both fruit, significantly increased during ripening and an extremely high level of butanoates was found in the over-ripe fruit. Sensory results indicated that with fruit softening, some of the changes in volatile content could explain changes in fruit flavor detected by a trained panel, and differences in characteristic flavor of the two cultivars. The results have implications for fruit sample handling and volatile assessment.     

The potential for commonly measured at-harvest fruit characteristics to predict chilling susceptibility of ‘Hort16A’ kiwifruit

The propensity for physiological disorders to arise during low temperature storage of kiwifruit is a significant commercial risk. The potential to use fruit characteristics (flesh colour, soluble solids content (SSC), dry matter and firmness) estimated non-destructively at harvest as markers for the susceptibility of ‘Hort16A’ kiwifruit to chilling injury (CI) has been investigated for individual fruit. While the fruit that developed CI during storage were some of the least advanced fruit on each orchard, the flesh colour, SSC, firmness and dry matter of the susceptible fruit differed considerably among orchards, such that there was not a clear minimum or maximum threshold for which fruit did or did not develop CI across all orchards. There was a large ‘orchard factor’ in the susceptibility of fruit to CI that was as important, if not more important, than the flesh colour, SSC, firmness and dry matter values. The ‘orchard factor’ may derive from a combination of environmental conditions and/or orchard management practices, in conjunction with fruit growth and development. Hence it is concluded that a generally applicable at-harvest prediction of ‘Hort16A’ fruit susceptibility to CI is not possible from an at-harvest non-destructive estimation of flesh colour, SSC, firmness and dry matter.     

玉米地方品种‘沃日黄’与‘沃30’重组后代配合力分析

为了评价‘沃30’与‘沃日黄’优株重组选系对配合力的改良效果及重组后代的育种潜势,探索地方品种优异基因发掘与利用新方法。以5个西南区骨干系及5个外引系为测验种,以‘沃30’及8个重组系为被测系（分别为‘W1’、‘W2’、‘W3’、‘W4’、‘W5’、‘W6’、‘W7’和‘W8’）,采用NCⅡ设计,对‘沃30’与8个重组系进行配合力及杂种优势分析。结果表明：被测系间株高、穗位高、穗长、穗行数、行粒数、百粒重、秃尖长、出籽率与单株产量等主要性状GCA差异显著或极显著;单株产量GCA效应值为‘W1’>‘W2’>‘W8’>‘沃30’>‘W4’>‘W5’>‘W3’>‘W6’>‘W7’;重组系‘W1’、‘W2’及‘W8’综合性状GCA效应值显著高于‘沃30’,具有较好的育种潜势。‘沃30’与‘沃日黄’优株混粉重组可以重新渗入并聚集初次选系过程中丢失的优良基因,获得更高配合力的重组系,利于优异地方种质的发掘与利用。     

‘寒富’ב岳帅’苹果杂交后代遗传多样性的SSR分析

本研究通过SSR标记,分析‘寒富’ב岳帅’杂交后代的遗传多样性。研究结果显示:20条SSR引物共扩增出54条带,其中多态性条带49条,多态性比率为90.7%,供试样品的基因多样性(H)和Shannon信息指数(I)分别为0.52和0.83。研究结果表明通过杂交,‘寒富’ב岳帅’杂交组合发生了基因的分离和重组,产生了丰富的遗传变异,可为今后育种提供优异种质材料。     

中华猕猴桃‘金阳’果实生长发育动态分析

研究南京地区‘金阳’猕猴桃果实发育规律,为其在南京及其周边地区的推广及优质丰产提供理论依据。以5年生‘金阳’猕猴桃为试验材料,定期观察并记录‘金阳’猕猴桃从坐果到成熟软化过程中的鲜重、干重、纵横径、种子发育和果肉颜色等形态指标,并测定可溶性固形物、可溶性糖、可滴定酸、有机酸、维生素C、叶绿素和类胡萝卜素等含量。结果表明,‘金阳’猕猴桃花后0～40 d果实迅速膨大,鲜重快速增加;花后20～116 d干物质不断积累;花后83 d种子开始变黑,花后97 d种子完全变黑成熟。‘金阳’果实成熟前,可溶性固形物变化幅度较小,可溶性糖含量呈上升趋势,维生素C和可滴定酸均呈先上升后下降的趋势,有机酸中奎宁酸、苹果酸、柠檬酸的含量较高。‘金阳’花后138～154 d,果实达到可采收状态。果实采收后,硬度迅速下降,并且类胡萝卜素/叶绿素的比值升高,果肉颜色由绿色转为黄绿色,再变为黄色。南京地区可食用状态下‘金阳’猕猴桃单果重为80.5 g,果肉金黄色,维生素C的含量为129 mg/100 g,可溶性固形物的含量为14%,可滴定酸的含量为1.4%,果实经济性状良好,因此‘金阳’猕猴桃适宜在南京地区推广。     

籼稻‘A232’及其后代对水稻卷叶螟田间耐害性观察

水稻卷叶螟是影响水稻高产稳产的重要迁飞性虫害之一,培育具有抗(耐)虫性的品种对水稻卷叶螟的绿色防控具有重要意义,而筛选、鉴定抗(耐)虫亲本材料是抗虫育种的基础。从2015年起,连续4年分别在海南陵水县和四川泸县田间条件下,通过小区对比试验观察‘A232’及杂交后代‘泸恢317’、感虫对照‘F77’的单株卷叶率及群体卷叶率田间表现,并对供试材料间群体卷叶率差异进行显著性测验。结果表明:2015年感虫对照‘F77’的群体卷叶率为10.5%,分别比‘A232’及‘泸恢317’高8.0%及9.6%;2016年‘F77’的群体卷叶率为74.9%,分别比‘A232’及‘泸恢317’高20.3%及28.0%,2年的差异均达5%显著水平。2017年秋播的‘A232’‘、泸恢317’及‘F77’群体卷叶率均在90%以上,且它们间差异不显著(P>0.05)。但‘A232’及‘泸恢317’的0级叶率分别比‘F77’高4.4%及8.7%,1级叶率分别比‘F77’高11.7%及22.1%,3级叶率分别比‘F77’低16.0%及30.4%,它们之间的差异均达5%显著水平。泸县观察表明‘A232’及‘泸恢31...     

蝴蝶兰‘大辣椒’和‘0436’杂交后代花部性状分离研究

为研究红色蝴蝶兰花性状遗传规律,解决国内蝴蝶兰主流品种‘大辣椒’易患煤污病的问题,以‘大辣椒’(Phalaenopsis‘Big chili’)和‘0436’(P.‘Red swan’)为亲本,进行正反交。研究结果表明:(1)蝴蝶兰‘大辣椒’和‘0436’正反交后代花色性状出现了显著的分离,花底色玫红色的深度出现了梯度变化,正反交后代的分离规律基本一致。花底色应是由多对基因控制的复杂遗传,且红色由显性基因控制,显性基因越多,花色越深。(2)蝴蝶兰花心颜色、花纹颜色和叶片性状可能为显性遗传。‘大辣椒’和‘0436’正反交后代的花心颜色、花瓣纹路、花期和叶片性状表现均倾向于‘0436’,可有效解决‘大辣椒’叶片易患煤污病的问题,杂交后代因分泌蜜露造成的煤污病发病率降低至25%以下。(3)‘大辣椒’和‘0436’正反交后代的花径、花朵数和花序长度平均值均低于双亲,中亲或超亲优势不明显。     

大花萱草‘黄油花’和‘粉秀客’杂交后代的鉴定与核型分析

为获得具有优良观赏性状的萱草新品种,以大花萱草‘黄油花’(H.‘Gleber’s Top Gream’)为母本,‘粉秀客’(H.‘Pink silk ruffle’)为父本进行杂交,获得了一些杂交后代,从中选出性状较稳定的4个杂交后代,综合利用形态学观察和核型分析进行了杂种鉴定。结果表明:4个杂交后代均遗传了父母本的形态学特征;双亲及其4个杂交后代均为二倍体(2n=2x=22),后代核型特征多介于父母本之间,以2B型为主。从形态学、细胞学方面证明杂交后代整合了亲本的遗传物质和表型特征,确定为真杂种,为利用大花萱草选育新品种提供了新的种质材料。     

葡萄‘红地球’与‘双优’杂交后代果实糖酸的遗传规律

为探索葡萄杂交后代果实糖酸含量的遗传规律,本研究以欧亚种‘红地球’和山葡萄‘双优’为亲本配置正反交组合,应用HPLC技术检测和分析葡萄亲本及其杂交后代果实中可溶性糖和有机酸组分。结果表明,葡萄果实中可溶性糖主要为葡萄糖和果糖,有机酸主要为酒石酸和苹果酸,糖酸组分及总糖和总酸含量在正反交后代中广泛分离,其中糖组分和总糖含量变异系数大于13%,有机酸组分及总酸含量变异系数大于31%,表明有机酸的选择潜力优于可溶性糖。杂交后代糖酸的广义遗传力(H2)存在较大差异:葡萄糖、果糖、总糖、酒石酸、总酸的H2较高,为0.73～0.93,表明这些性状的变异主要来自遗传效应,遗传潜能大。苹果酸的H2较低,正交组合为0.59,表明苹果酸的遗传效应小,易受环境影响。杂交后代糖含量在40.07～282.29 mg/g FW范围内呈正态分布,有机酸含量在0.23～13.88 mg/g FW范围内呈正态分布。正反交组合差异较大:正交组合后代糖含量高于亲中值,表现为超亲遗传,酸含量接近于亲中值,呈趋中变异;反交组合后代糖含量低于亲中值,呈衰退变异,酸含量高于亲中值,呈增强变异。正反交组合后代有机酸含量均倾向于母本,存在一定程度的母性遗传倾向。本研究结果为葡萄育种选配亲本提供依据。     

‘寒富’ב四倍体嘎拉’苹果的三倍性杂交后代ISSR和AFLP分析

利用ISSR及AFLP分子标记技术研究了‘寒富’ב四倍体嘎拉’苹果的7份三倍性后代及其亲本的遗传变异。结果表明ISSR扩增得到的遗传多样性指数中扩增多态性比率(PPB)为60.00%,观察等位基因数(Na)为1.600,有效等位基因数(Ne)为1.420,Nei’s基因多样性指数(H)为0.236,Shannon信息指数(I)为0.346;均小于AFLP扩增的遗传多样性指数66.54%、1.665、1.421、0.240和0.357。根据ISSR和AFLP得到的UPGMA聚类图显示这7份三倍性杂交后代倾向于母本‘寒富’。在三倍性苹果遗传多样性检测上AFLP优于ISSR,且这7份三倍性新种质在遗传上倾向于母本遗传。为三倍性苹果育种的亲本选择提供依据。     

蝴蝶兰‘大辣椒’(Phalaenopsis ‘Big chili’)和‘0436’(P. ‘Red swan’)杂交后代花部性状分离研究

为研究红色蝴蝶兰花性状遗传规律,解决国内蝴蝶兰主流品种‘大辣椒’易患煤污病的问题,以‘大辣椒’(Phalaenopsis‘Big chili’)和‘0436’(P.‘Red swan’)为亲本,进行正反交。研究结果表明：（1）蝴蝶兰‘大辣椒’和‘0436’正反交后代花色性状出现了显著的分离,花底色玫红色的深度出现了梯度变化,正反交后代的分离规律基本一致。花底色应是由多对基因控制的复杂遗传,且红色由显性基因控制,显性基因越多,花色越深。（2）蝴蝶兰花心颜色、花纹颜色和叶片性状可能为显性遗传。‘大辣椒’和‘0436’正反交后代的花心颜色、花瓣纹路、花期和叶片性状表现均倾向于‘0436’,可有效解决‘大辣椒’叶片易患煤污病的问题,杂交后代因分泌蜜露造成的煤污病发病率降低至25%以下。（3）‘大辣椒’和‘0436’正反交后代的花径、花朵数和花序长度平均值均低于双亲,中亲或超亲优势不明显。     

观赏与食用兼备的猕猴桃新品种‘满天红’

猕猴桃属植物中以中华猕猴桃（Actinidia chinensis）的原变种（A．chinensis var．chinensis）和美味猕猴桃（A．chinensisis var．deliciosa）变种的分布最广,自然蕴藏量最大,果实最大,且经济价值最高。     

毛花猕猴桃‘赣猕6号’主要生物学特性研究

为了对‘赣猕6号’的推广及制定合理栽培管理措施提供参考依据,试验采用田间观测与室内测试相结合的试验方法对其主要生物学特性进行观测研究。结果表明,在江西省奉新地区,伤流期在2月中旬,初花期在5月上旬,谢花期在5月下旬,果实成熟期在10月下旬,为晚熟品种;根系浅,肉质,以须根为主;花单性,二歧聚伞花序,平均单株花量为550～675朵,花红色,极具观赏性;以中果枝和长果枝结果为主,分别占66.0%与28.5%;果实为长圆柱形,平均单果重72.5 g,最大单果重96 g;果实的Vc、总糖、可滴定酸以及SSC平均含量分别为829.23 mg/100g、11.31%、1.32%和14.42%。毛花猕猴桃‘赣猕6号’生物学性状遗传稳定,具有较高的发展前景。     

贵州西部‘红阳’猕猴桃溃疡病与温湿气象条件的联系

为了研究温湿气候变化对‘红阳’猕猴桃溃疡病发生的影响,以‘红阳’猕猴桃为试材,基于2013—2018年贵州猕猴桃主要种植区的水城县猴场、米箩、勺米、六枝特区郎岱、盘州市普古共5个试验区3—4月溃疡病监测资料以及同期温度、湿度、持续降雨日数资料,运用数理统计方法,分析溃疡病发生和流行与温度、湿度、持续降雨日数的联系。结果表明：‘红阳’猕猴桃溃疡病始发的气象条件为持续4天及以上有降水天气（日降水量≥0.1 mm）出现,且日平均温度≤15.0℃、日平均相对湿度≥80%,同时溃疡病始发之后继续维持1天及以上的低温阴雨高湿天气;溃疡病流行的气象条件为持续4天及以上有降水天气（日降水量≥0.1 mm）出现,且日平均温度≤18.0℃、日平均相对湿度≥80%,同时溃疡病流行之后继续维持1天及以上的低温阴雨高湿天气。贵州西部‘红阳’猕猴桃溃疡病的发生、流行对温湿变化有较好的响应。     

‘龙麦35’与寒地多年生麦草杂交后代的分子细胞遗传分析

本研究利用黑龙江省哈尔滨地区冬季寒冷的气候特点以及形态学和分子细胞遗传学研究手段,对‘龙麦35’与6份寒地多年生麦草杂交后代F1进行选育和分析。结果表明,寒地多年生麦草同中间偃麦草染色体组构成一致,具有出色的抗寒性;寒地多年生麦草1-1-4和7-31花期同‘龙麦35’同步,杂交结实率明显高于其他组合。杂种F1为两亲中间型,植株成活率低,减数分裂时期寒地多年生麦草的染色体可同‘龙麦35’染色体发生配对,但染色体组配对不完全,单价体数量多于二价体,导致植株不育。F₁植株虽不具有抗寒性,但具有割后再生性。8个F₁株系,仅株系F₁18731结实,GISH检测结果表明,F₂18731染色体组带有27条‘龙麦35’染色体,14条麦草染色体和1条小麦-麦草易位染色体,染色体数为42条。本研究可为寒地多年生麦草染色体组的研究和利用提供理论基础。     

采收成熟度对‘金艳’猕猴桃果实品质及香气成分的影响

以不同采收期的中华猕猴桃‘金艳’为试材,研究不同采收成熟度对果实品质及香气种类和相对含量的影响。以盛花期后110天为第一次采样时间,之后每隔10天采一次样,共采样6次（采收期Ⅰ~Ⅵ）。果实采收后立即测定外观品质和内在品质,于果实达可食状态后测定果实内在品质,并采用固相微萃取-色谱-质谱联用法(SPME-GC-MS)分析可食期果实香气成分。结果表明,采收期越晚,单果重越大,果实可溶性固形物含量越高。采收期Ⅵ果实硬度较前期急剧下降。采收期Ⅴ果实达到可食时的总酸含量最低,固酸比及总抗坏血酸含量最高,对香气成分分析时发现酯类种类最多,相对含量最高。研究认为‘金艳’猕猴桃在采收期Ⅴ时,果实适宜采收,果实可食期内在品质最好,酯类香气种类最多,果实可溶性固形物在7.5%左右,总酸含量在1.3左右,固酸比在5.5左右。