Rheological and chemical predictors of texture and taste in dessert banana (Musa spp.)

To be able to account for sensory qualities earlier in the assessment of a new banana hybrid in a selection scheme, predicting the sensory perception of banana texture and taste by instrumental parameters was investigated. Thirteen cultivated banana and four new triploid hybrids were characterized by sensory profiling, and rheological and chemical analyses. Multilinear regressions were used to calibrate predictions using 13 cultivated bananas, and the quality of predictions was validated using four hybrids. The sensory characteristics sourness and sweetness were predicted by titratable acidity (R² = 0.68) and pH (R² = 0.66). Malate and citrate were the main contributors to sweetness and sourness. Astringency was predicted by total tannins (R² = 0.55). Rheological parameters from texture profile analyses (stress at fracture, fracturability) were more suitable than pulp puncture force to predict the sensory texture properties firmness (R² = 0.47) and melting (R² = 0.60). These textural properties were predicted by titratable acidity and dry matter content (R² = 0.62). Predictions of mealiness, adhesiveness, and heterogeneity were not efficient. Differences of 3.6–3.7 meq 100 g⁻¹ FW in titratable acidity or of 0.30 g 100 g⁻¹ FW in malate or citrate were required to ensure a detectable difference in sourness or sweetness (p = 0.9). Pulp puncture force needed to differ by a minimum of 0.9 N before a difference in firmness could be perceived by the panelists. In conclusion, while models to predict sourness and sweetness can now be used for high throughput phenotyping, we recommend additional tests for other sensory attributes.     

小麦系选品种与其亲本的遗传差异分析

为了解小麦系选品种与其亲本间遗传物质的传递特点,利用分布于小麦全基因组的522个SSR标记和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)对7个系选品种及其亲本进行了分析.总体来看,UPGMA聚类和品种间遗传距离分析结果与品种间亲缘关系有较好的一致性,7个系选品种与其亲本间不同位点的比例平均为25.3％,其中昌乐5号与亲本济南4号有118个(22.6％)不同位点,北京14与其衍生的6个姊妹系品种存在差异的位点数在79～179之间,分别占全基因组遗传信息的15.1％～34.3％.从基因组和染色体来看,系选品种与其亲本的遗传差异较大,其中红良5号在1A、7A、1B和4D染色体,冀麦2号在1D染色体,京双3号在7D染色体,分别与亲本北京14不同位点的比例等于或超过50.0％.高分子量麦谷蛋白亚基分析发现,7个系选品种分别与他们的亲本高分子量谷蛋白亚基组成相同.     

High Risk of the Formation of Milky White Rice Kernels in Cultivars with Higher Potential Grain Growth Rate under Elevated Temperatures

Abstract

Our objective was to clarify whether rice cultivars with a higher grain dry-matter increase rate (GIR) under elevated temperature condition show a higher percentage of milky white rice kernels (MWK). The rate of MWK judged using a rice-quality selector significantly varied with the cultivar and experimental year. The spikes of the cultivars detached 5–7 days after heading were solution-cultured with an adequate nutrient supply for one week at 25, 28 and 33ºC. GIR was overall the highest at 28ºC, and GIR at this temperature was considered to reflect the potential GIR in all the grains tested. There was a close correlation between the rate of MWK and the GIR at 28ºC under field conditions when temperatures during the grain-filling period were approximately over 25ºC. It was suggested that cultivars with a higher potential GIR under elevated temperature conditions have a higher risk of the formation of MWK.     

Proteins and Carbohydrates in Developing Rice Panicles with Different Numbers of Spikelets: —Cultivar difference and the effect of nitrogen topdressing—

Abstract

Proteins and carbohydrates in developing rice panicles were analyzed to see whether these parameters control spikelet number in rice. Two rice cultivars and 2 levels of nitrogen topdressing were used to obtain panicles with different numbers of spikelets. A japonica rice cultivar, Nipponbare, with topdressing (H) had 1.8 times more spikelets per panicle than that without topdressing (L). Moreover, the number of spikelets per panicle in an indica rice cultivar, Takanari, without topdressing was 2.7 times larger than that in Nipponbare-L. Panicles with more spikelets (LP) in Nipponbare-H and Takanari-L showed slower growth than those with few spikelets (SP) in Nippanbare-L in an early stage. LP, however, increased markedly in size thereafter, eventually exceeding SP, in length and fresh weight. Soluble protein content was higher in LP than SP in an early stage, but this difference was hardly detected in a late stage. No clear difference was observed in sugars or starch between LP and SP. Analysis of soluble and insoluble proteins by SDS-polyacrylamide gel electrophoresis showed that bands corresponding to insoluble proteins with a molecular weight about 42 kDa were present at higher intensities in LP than in SP. These results suggest that the spikelet number in rice is controlled by the soluble protein content in an early stage and insoluble proteins with a molecular weight of 42 kDa during panicle development, but not by the carbohydrates in developing panicles.     

北海市春季甜玉米品种评价研究

[目的]为评选出丰产性好、抗逆性强、生育期适宜北海市栽培的的玉米(Zea mays L.)品种,解决北海市玉米生产中存在品种单一、退化的问题,促进种植业结构调整。[方法]对14个玉米品种进行了品种比较试验。[结果]CD002综合表现最好,金中玉、兆珍2号、HST7-02综合表现较好,以上4个品种适合北海市种植。[结论]该研究可为玉米新品种的鉴定和推广提供科学依据,带动玉米产业的发展。     

烤烟外引品种NC 71烟叶样品质量研究

本研究以NC 71与对照品种K 326和NC 89在南北烟区9个省(市)的10个种植试点的烟叶样品为试材,在外观质量、常规化学成分、常规烟气成分、感官质量、主要致香成分五个方面进行了分析比较,结果表明NC 71在外观质量上与南北烟区对照品种K 326和NC 89相当,部分NC 71样品身份或油分稍好于对比品种;未检测出碱糖、碱氮、钾氯比值都较协调或是都不协调的样品,部分NC 71样品钾氯或碱糖和钾氯比值较协调。南方烟区湖南永州的NC 71样品碱糖和碱氮比值不协调;NC 71在焦油、一氧化碳和烟碱含量上总体高于照比品种;南北烟区种植试点的NC 71样品综合感官质量表现较好;北方烟区三种植试点NC 71致香物质总量优于NC 89,南方种植试点NC 71与K 326在致香物质含量上各有优势。     

永州地区早春大棚甜瓜新品种引进比较试验

为筛选出适宜永州地区早春大棚种植的甜瓜新品种,通过随机区组设计,对6个参试甜瓜品种进行比较。试验结果表明,脆禧表现为早熟,一品红、玉菇生育期与CK(雪峰蜜2号)接近,3个品种均表现高产,且商品性、口感、含糖量较优,因此认为脆禧、一品红、玉菇这3个品种适宜在湖南永州地区推广种植。     

云南不同花魔芋品种性状相关分析

对云南不同生态区域种植的魔花15、楚雄花魔芋2号、丽江花白魔芋、会泽花魔芋、大关花魔芋和富源花魔芋(CK)6个云南花魔芋地方品种的主要性状进行了相关性和聚类分析。分析结果表明,花魔芋种芋大小、干物质含量、球茎高等对球茎质量影响较大;干物质含量、球茎直径、球茎高等与葡甘露聚糖含量呈显著性相关;球茎质量、葡甘露聚糖、球茎直径等与干物质含量呈显著相关。云南花魔芋品种可聚为3个类群,富源花魔芋、会泽花魔芋、大关花魔芋和魔花15分布在第1个类群里,丽江花白魔芋、楚雄花魔芋2号分别聚成另外2个类群。     

不同熟期小麦品种光合性能的初步研究

利用ＢＡＵ便携式光合蒸腾测定仪系统测定了早熟品种河农３２６和中熟品种冀麦２４号以光合速率为主的光合性能。结果表明,河农３２６较冀麦２４号出叶早,叶片功能期长,顶部叶片光合速率到达峰值早,光合作用的高值持续期较长,起身至技节阶段单茎光合速率较高。单茎各叶单位叶面积的平均光合速率也有一定优势,这为早熟高产提供了光合生理基础。同时,由于其叶面积较小,在栽培实践中适当密植,是保证其获得高产的群体生理基础。     

华北地区小麦品种更替过程中叶片细胞形态和光合性能演替规律的研究──Ⅰ.叶片细胞形态的演替

以华北地区自50年代开始至今各年代大面积推广的19个代表性冬小麦栽培品种为材料,对其春生第1,3,5,6叶的叶片细胞形态进行了系统观察。主要结果表明,随品种由远及近的更替顺序,同一叶位叶片叶肉细胞中多环细胞的频率逐渐提高,叶肉细胞变小,旗叶叶肉厚度增加,叶肉细胞层数增加。这表明,随品种更替,叶片细胞的形态和组成有逐渐复杂化的趋势,而这种变化可能是和光合能力的提高有关的。