气调箱贮藏甜樱桃品质变化研究

本文以美早和萨米脱为试材,研究了气调箱保鲜处理对果实贮藏品质变化的影响。结果显示,甜樱桃贮藏过程中,气调箱内CO2浓度基本维持在12-15%;气调箱处理甜樱桃果实硬度显著高于对照果实,轻微降低了可溶性固形物的含量;但却保持了果实较高的可滴定酸含量以及维生素C含量。气调处理最明显的效果就是降低了甜樱桃果实的腐烂率。两品种相比较,萨米脱的腐烂率要远低于美早,耐贮性较好。两品种果实0oC贮藏60 d后仍具有较好的感官品质,并可以保证3 d的常温货架期。     

不同品种甜樱桃果实贮藏期间品质及生理特性变化

以“砂蜜豆”、“拉宾斯”、“雷尼”、“萨米脱”、“奇好”5个晚熟甜樱桃品种为试材，研究自发气调包装（MAP）结合低温贮藏（0±0.5）℃条件对5个品种甜樱桃贮藏期间的果实品质及生理特性的影响，探索不同品种甜樱桃品质及耐贮性差异。结果表明：①采收时，“雷尼”果实硬度、可溶性固形物含量和固酸比最高，品质最佳，“砂蜜豆”果实硬度、可溶性固形物及抗坏血酸含量最低，品质最差；贮藏期间，“奇好”果实硬度下降最少，为14.3%；“砂蜜豆”可溶性固形物含量升高3.5%，其余品种均有所降低；“砂蜜豆”可滴定酸和抗坏血酸含量损失最小，分别下降40.5%和53.0%；②“拉宾斯”和“萨米脱”果实失重率最低，分别达到4.5%和7.3%；“拉宾斯”和“萨米脱”果柄保鲜指数最高，分别为72.4和67.3；“拉宾斯”果实乙醇含量升高最低，为0.068 g/kg；“拉宾斯”、“雷尼”和“萨米脱”果实腐烂率最低，分别达到18.2%、20.1%和23.4%；“雷尼”和“奇好”果面颜色饱和度降幅最小，降幅分别为10.7%和9.1%；③“萨米脱”和“拉宾斯”花青素、总酚和类黄酮含量最高，超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性较强，有较高的抗氧化能力；④“拉宾斯”、“奇好”和“萨米脱”保鲜袋内的气体成分变化较大，自发气调能力较强。综合考虑贮藏期内各因素的差异变化，5个品种耐贮性好差顺序依次为：“拉宾斯”＞“萨米脱”＞“雷尼”＞“奇好”＞“砂蜜豆”。     

不同浓度臭氧处理对采后猕猴桃货架期间质构性能的影响

为探讨不同浓度臭氧处理对猕猴桃果实质地的影响,以"贵长"猕猴桃为试材,在(0±0.3)℃冷藏条件下贮藏120 d后进行货架试验,研究果实的腐烂情况,并应用质地多面分析法(TPA)对猕猴桃果肉质地参数差异变化进行研究。结果表明:臭氧能够抑制猕猴桃果实腐烂率的上升,浓度为200 mg/L的臭氧处理对果实腐烂率的抑制效果最好,货架结束时(12 d),果实腐烂率仅为13.71%;果实的硬度、弹性、凝聚性、咀嚼性和回复性相互之间均有较好的相关性,但黏着性与其他指标相关性较差,所以用硬度、弹性、凝聚性、咀嚼性和回复性作为评价猕猴桃质构性能的主要参数;与对照比较,臭氧均可更好地保持猕猴桃果实的硬度、弹性、凝聚性、咀嚼性和回复性等质构性能,其中200 mg/L臭氧处理效果优于浓度为100 mg/L和300 mg/L的臭氧处理组。因此,采后用200 mg/L臭氧处理猕猴桃能够保持果实较好的保鲜效果,更好地维持果实的质构性能。结果还表明,猕猴桃的腐烂率(x)与果肉硬度(y)在一定范围内呈现良好的线性关系,提出了拟合回归方程(y=0.244x2-24.39x+708.8,R2=0.915)用于臭氧处理猕猴桃货架期果肉质地变化的评价依据。     

金冠苹果冷藏不同时间1-MCP处理对果实质地的影响

金冠苹果于(0±0.5)℃下冷藏不同时间(0、12、24 d)用1-MCP(浓度1μL/L)进行处理,采用质构仪质地多面分析法(TPA)测定不同处理果实的果肉质地参数,研究冷藏不同时间1-MCP处理对金冠苹果保鲜效果的影响。结果表明,果肉脆度与咀嚼性呈显著正相关,与黏着性呈显著负相关;果肉硬度与凝聚性、咀嚼性分别呈显著、极显著正相关;果肉凝聚性与回复性、咀嚼性呈显著正相关;果肉黏着性与其他质地指标均呈负相关。各1-MCP处理组均能够延缓果实脆度、凝聚性、回复性、咀嚼性的降低,抑制黏着性的增加,从而延缓果实的软化,但其作用效果会随着处理时间的延后而降低。所以,金冠苹果采用1-MCP处理的时间以冷藏后不超过12 d为宜。     

广东鲜食橄榄果实质构特性比较

为比较分析广东省主要鲜食橄榄果实质构特性的差异,探讨鲜食橄榄果实质地评价的量化参数,验证感官评价质地的有效性。采用质构刺穿试验法对7个优质鲜食橄榄品种果肉质构参数和2种水肥管理方式不同成熟期的‘香甜榄’果实品质进行测定和比较分析。结果表明,不同品种之间果肉的各质构参数变异系数为12.57%~23.95%,差异性显著,与感官评价一致;果皮强度与果皮脆性和果皮韧性均呈显著正相关,果皮破裂深度与果肉硬度呈显著负相关。采用本次试验栽培管理方式可以提高橄榄完熟果实可溶性固形物6%、可滴定酸3.5%、单宁54.9%、果皮强度12.7%、果皮脆性23.5%,降低粗纤维10%、果皮韧性13.7%。果实质地品质参数主成分分析表明,果皮强度、果实硬度和纤维指数可作为质地参数量化区分不同品种间的差别,并明确果皮强度、果实硬度分别小于2300、1600 g和纤维指数大于10,为鲜食橄榄果肉质地品质较好的数值范围。研究初步建立了利用质构刺穿试验法量化评价鲜食橄榄果实质地品质的方法。     

不同机械损伤对葡萄果实质地的影响

以红地球葡萄果实为试料,采用质构分析法（TPA）研究了不同高度跌落机械损伤对葡萄果粒感官品质及质地变化的影响,并分析各指标相互关系。结果表明：葡萄果实经不同高度机械跌落后,随着跌落高度的增加,其感官品质发生很大变化;当跌落高度小于60 cm时,外观观察无明显差异,当跌落高度≥80 cm后,外观差异明显,损伤的果粒数量和损伤级数均增加明显;损伤指数与跌落高度回归拟合度高（R2=0.985）,100 cm和160 cm高度跌落时,损伤指数分别是60 cm处理的4倍和8倍之多;随跌落高度的增加,果实硬度和咀嚼性值呈下降趋势,80~160 cm处理下降幅度明显大于其他处理;果实弹性、凝聚性和回复性呈增加趋势,80~160 cm处理均与对照呈极显著差异（P＜0.01）,100 cm和160 cm处理凝聚性分别增加了24.5%和31.0%,回复性大于其他3个处理;机械损伤指数与硬度、咀嚼性、胶黏性呈负相关性,与凝聚性和弹性、回复性呈正相关。     

不同品种板栗质地分析

以采自河北、河南两省的6种板栗品种(塔丰、遵玉、早丰、大板红、红油栗、大板栗)为试材,采用质构仪质地多面分析法对其进行分析测定,比较不同品种板栗的果仁质地特性,探讨反映板栗果实质地状况的评价参数。结果表明,不同品种间质地构成和变化特性存在较大差异,其中大板红在硬度、胶黏性方面最高,大板栗品种在弹性、胶黏性、咀嚼性方面较好,在果仁内聚性方面最好的为塔丰。板栗各质地参数间的相关性表明,硬度与咀嚼性、胶黏性呈显著正相关(P0.05),内聚性与胶粘性、咀嚼性呈显著正相关(P0.05),弹性与胶黏性、咀嚼性呈一定的负相关,胶黏性与咀嚼性呈极显著正相关(P0.01),故硬度、内聚性、咀嚼性均能较好地反映板栗的质地特性。     

不同保鲜剂处理对“巨峰”葡萄货架期品质的影响

以“巨峰”葡萄为试材，分别用9.0 μg/L ClO2气体密闭熏蒸30 min和2.8 g/L L-半胱氨酸溶液处理葡萄，并通过测定果实的质地品质、可溶性固形物、可溶性糖、可溶性蛋白、VC、丙二醛（MDA）含量、过氧化物酶（POD）及多酚氧化酶（PPO）活性的变化，研究不同化学保鲜剂对葡萄采后常温贮藏品质的影响。结果表明，2.8 g/L L-半胱氨酸处理能有效维持常温贮藏葡萄果实的硬度、弹性、咀嚼性、胶着性、凝聚性、回复性等质地性能和果实的色泽等感官品质，并可有效延缓果实可溶性固形物、可溶性糖、可溶性蛋白、VC含量的下降，同时可抑制果实MDA含量和PPO活性的增加，并保持较高的POD活性。因此，2.8 g/L L-半胱氨酸处理能较好地保持果实的质地、色泽、营养品质，并能有效提高采后葡萄的抗病性。     

不同处理对采后芒果质构的影响

为明确外源乙烯和成熟抑制剂对采后芒果质构性能的影响效果,以"红玉"芒果为试验材料,在15℃,相对湿度85％环境下贮藏,分别于采后0、4、8、12、16、20、24 d采用质地多面分析(TPA)法对乙烯、1-甲基环丙烯(1-MCP)和赤霉素(GA3)处理的果实进行质构的测定.结果表明:乙烯处理后,芒果果实的硬度、脆度、咀嚼性、胶着性、弹性、黏聚性、回复性快速下降,而黏性快速上升,并且随着乙烯浓度的增加,脆度下降的更快,而咀嚼性和胶着性反而下降得更慢;1-MCP和GA3处理均能使芒果果实的硬度、脆度、咀嚼性、胶着性、弹性、黏聚性、回复性保持较高的水平,延缓黏性的上升;相关性分析表明,硬度和脆度、咀嚼性、回复性之间呈极显著正相关,黏性分别与咀嚼性、胶着性呈极显著负相关.采用TPA法能很好地评价芒果果实的质构.乙烯处理能加速芒果质构的变化,1-MCP和GA3处理能延缓采后芒果果实的质构变化,且以1-MCP处理效果较好.     

5个秋葵品种果实性状、质地、营养品质及抗氧化性比较

秋葵果实具有食用和药用价值,用于生产保健食品和治疗多种疾病。比较了5个不同品种秋葵（咔里巴、红秋葵、杨贵妃、绿白一号、纤指）果实的性状、质地参数（硬度、黏着性、弹性、凝聚性、咀嚼性和回复性）、营养品质（总糖、还原糖、游离氨基酸、蛋白质、维生素C和粗纤维含量）以及抗氧化能力的差异。结果表明,绿白一号果实的各指标综合表现最优,可作为秋葵品质育种的重要材料。     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Relation between wheat-rye crossability and seed set of common wheat after pollination with other species in the Hordeae

Summary Cultivars of common wheat (Triticum aestivum L. em. Thell.) of high wheat-rye (Secale cereale L.) crossability set more seed with pollen of other related species than did wheats of low wheat-rye crossability. This was found to be true for pollen parents from the genera Triticum, Aegilops, Secale, Agropyron and Elymus.     

Breeding apomictic bahiagrass (Paspalum notatum Flügge) with improved turf traits

The development of a turf‐type bahiagrass could have a remarkable impact on the billion‐dollar turf industry in the south‐eastern United States. The goals of this study were to (i) select bahiagrass genotypes with improved turf attributes and (ii) determine the reproductive mode and seed fertility of selected genotypes. The population included mutants, wild types, hybrids and standard cultivars evaluated at two locations for two years. Morphological variation was observed and clonal repeatability (H²) ranged from 0.27 to 0.90. Flowering was extremely reduced in some mutants, which also exhibited dark green colour, finer texture and reduced canopy height. Cytoembryological observations revealed that diploids reproduced sexually and tetraploids by obligate or facultative apomixis. Genotypes with superior seed fertility were identified, while others were comparable to the standard cultivars. While mutant plants exhibited great morphological variation, the random mutations did not affect their reproductive mode, validating the use of mutagenesis in apomictic species. The high H² indicated that selection for improved turf attributes could be successfully performed with the advantage of clonal seed propagation.     

Inheritance of fruit colour in a wild Russian red raspberry seedling

Summary A new gene, i, from a self-incompatible wild Russian Rubus idaeus seedling is described. The gene i interacts with the fruit colour gene T, Tii plants having apricot instead of red fruits, and spines, leaves and stems pigmented to varying degrees. A deficit of apricot-fruited seedlings in progenies segregating for i could be explained by linkage between i and the self-incompatibility S locus with a crossover value of approximately 26.7%.Segregations for spine colour in crosses and backcrosses of the Russian seedling with two green-spined (ttII) raspberries selected for their yellow fruit colour, showed that both the latter carried the spine colour intensifier gene P. This suggests that earlier authors were incorrect in attributing the apricot fruit colour developed by some tt plants to a pleiotropic effect of P.     

Flag Leaf Senescence, as Evaluated by Numerical Image Analysis, and its Relationship with Yield under Drought in Durum Wheat

Senescence was evaluated at different stages of the grain‐filling period in eight durum wheat varieties using numerical image analysis (NIA). The varieties were grown under early, severe drought conditions on the high plains of Sétif in Algeria. After flowering, three different irrigation treatments were applied. Treatment effect was small, while a genotypic effect was noted for most of the senescence parameters. Senescence correlated to biomass, while the maximal rate of senescence, V_smax, correlated to thousand‐kernel weight. The potential of the method of numerical image analysis for monitoring flag leaf senescence, detecting genotypic variability and selecting genotypes with delayed senescence is discussed.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Cowpea (Vigna unguiculata): Genetics,genomics and breeding

Cowpea, Vigna unguiculata (L.), is an important grain legume grown in the tropics where it constitutes a valuable source of protein in the diets of millions of people. Some abiotic and biotic stresses adversely affect its productivity. A review of the genetics, genomics and breeding of cowpea is presented in this article. Cowpea breeding programmes have studied intensively qualitative and quantitative genetics of the crop to better enhance its improvement. A number of initiatives including Tropical Legumes projects have contributed to the development of cowpea genomic resources. Recent progress in the development of consensus genetic map containing 37,372 SNPs mapped to 3,280 bins will strengthen cowpea trait discovery pipeline. Several informative markers associated with quantitative trait loci (QTL) related to desirable attributes of cowpea were generated. Cowpea genetic improvement activities aim at the development of drought tolerant, phosphorus use efficient, bacterial blight and virus resistant lines through exploiting available genetic resources as well as deployment of modern breeding tools that will enhance genetic gain when grown by sub‐Saharan Africa farmers.     

Screening for resistance to take-all in wheat,triticale and wheat-triticale hybrid lines

Summary Fifteen triticale and wheat-triticale hybrid lines were evaluated for resistance to the take-all fungus Gaeumannomyces graminis var. tritici and compared with five wheat and two rye lines in inoculated field and pot trials. The triticale and wheat-triticale hybrid lines varied in rye chromosome number and degree of resistance expressed. One line, Venus with seven pairs of rye chromosomes consistently showed levels of resistance intermediate between wheat and rye. A trend was observed where increasing rye chromosome content led to greater resistance but exceptions showed that variation within triticales could not be ascribed to rye chromosome content alone.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.