Changes in endogenous abscisic acid and soluble sugars levels during dormancy-release in bulbs of Lilium rubellum

Changes in endogenous abscisic acid and soluble sugars levels during dormancy-release of lily bulbs of Lilium rubellum were investigated. Shoot emergence and flowering of the bulbs stored for 14 weeks at 4 °C occurred more synchronously, and the time span from first to last flower in the plants was shorter than those of bulbs stored for 10 weeks at 4 °C. Longer duration of bulb storage showed accelerating effects of increasing leaf number and stem length but negatively affected flower size. Flower number per plant was not much influenced by bulb storage duration. Concentration of endogenous abscisic acid (ABA) level in the bulbs during bulb storage decreased as storage duration increased, and it remained at a constant level after being stored for 10 weeks. This result suggests that the decrease in the endogenous ABA level during bulb storage is correlated with dormancy-release. Concentrations of soluble sugars also changed during bulb cold storage. Sucrose concentration increased as the chilling term increased to 10 weeks but decreased afterward. Glucose and fructose increased from the beginning of chilling to the end of a 14-week cold storage.     

Starch granule size variation and relationship with tuber dry matter content in heritage potato varieties

Heritage potato varieties in Canada are historic old varieties collected from Canada and various countries before the formal establishment of the Canadian plant variety registration system and may be a valuable gene resource for beneficial traits in potato breeding and bioproducts development. Greater evaluation is the key for the enhanced use of these materials. It is unknown how much variation of starch granules occurs among Canadian heritage potato varieties. We analyzed the starch granule size of 14 potato heritage varieties held in the Canadian Plant Gene Resources collection over 2 years using a squeezed juice and microscopic method recently developed at the Potato Research Centre. The varieties demonstrated considerable variation in starch granule size and shape. The granules showed average lengths ranging from 18 μm in the variety Congo to 32 μm in ‘Russet Burbank’. The largest single granule measured from 64 μm in ‘Congo’ to 91 μm in ‘Crotte d’Ours.’ The granule sizes of the varieties showed a very high correlation (r = 0.975, P < 0.0001) between years. This high reproducibility suggests the existence of genetic factors in determining starch granule size. We also found that the starch granule size is positively correlated with tuber dry matter (in terms of specific gravity) in these heritage potatoes. The results demonstrated reproducible genotypic variation for starch granule size and shape in tubers with a significant correlation to tuber dry matter in these heritage potato varieties, and offers the possibility for and agronomic relevance of genetic modification of starch granules through selective breeding.     

温室甜瓜光合生产与干物质积累模拟模型研究

在借鉴国内外温室蔬菜作物光合生产和干物质积累模拟模型的基础上,根据温室甜瓜的试验数据,确定有关模型参数,建立了温室甜瓜光合生产与干物质积累模拟模型,模型包括叶面积指数、光合生产及干物质积累动态模型。模型利用比叶面积法建立了叶面积指数动态模型,光合作用模型还引用简便有效的高斯积分法计算冠层每日的总同化量,不但考虑了光合有效辐射的日变化规律,而且考虑了太阳高度角的变化对冠层反射率的影响和温度对呼吸作用的影响。通过不同品种干物质积累动态模型检验表明,模型机理性、通用性和精度较好。     

温室小型西瓜光合生产与干物质积累模拟模型

在借鉴国内外温室蔬菜作物光合生产和干物质积累模拟模型的基础上,根据温室小型西瓜的试验数据,确 定有关模型参数,建立了温室小型西瓜光合生产和干物质积累模拟模型,模型包括叶面积指数动态模型、光合生产 动态模型和干物质积累动态模型。模型利用有效积温对叶面积指数LOGISTIC方程建立叶面积指数动态模型,同时 光合作用模型还引用简便有效的高斯积分法计算冠层每日的总同化量,既考虑了光合有效辐射的日变化规律,又考 虑了太阳高度角的变化对冠层反射率的影响;此外,模型还考虑了温度对呼吸作用的影响,确定了温室小型西瓜的 碳水化合物转化成干物质的系数CF。通过不同品种、不同播期下的干物质积累动态的模型检验,表明模型有较强的 精确性、机理性和实用性。     

Cropping effects on the loss of apple fruit firmness during storage: The relationship between texture retention and fruit dry matter concentration

Firmness is a primary measure of apple fruit texture, the key determinant of eating quality of apples. Despite the well developed understanding of the process of firmness loss in storage, there is very limited information concerning pre-harvest and at-harvest causes of the variation in fruit quality in the marketplace. The objective of the present study was to investigate the respective roles that the factors of time and intensity of crop thinning, fruit size and fruit dry matter concentration (DMC) each may have in determining fruit firmness of ‘Royal Gala’ apple at harvest and during storage. Loss of firmness during storage of all thinning treatments and of fruit size and DMC categories was described by a bilinear equation. Time of thinning did not influence any aspect of fruit softening during air storage at 0.5 °C. Comparing the crop loads, a lower crop load (100 fruit per tree) resulted in firmer fruit at harvest. The loss of firmness during storage associated with crop load occurred because fruit from the lowest crop load softened more rapidly during the second slow phase of softening. Fruit firmness was positively correlated with fruit size where larger fruit were slightly firmer than smaller fruit at harvest but not after storage. The softening profiles of different sized fruit were similar except for a class of extremely small fruit, which appeared to soften more rapidly during the second slow softening phase of storage. Both at-harvest and post-harvest fruit firmness were influenced by fruit DMC. Fruit firmness at harvest increased significantly as fruit DMC increased from 13% to above 16%. Despite having significantly different initial firmness, all fruit classes with DMC higher than 13% softened at a similar rate during both the initial rapid and second slow softening phases and the transition between the two phases occurred after the same time in storage. In contrast, fruit with very low DMC, less than 13%, had a greater rate of softening in the second phase. These results indicate that variation in fruit firmness at harvest and after storage is influenced by processes that affect and alter fruit DMC during fruit development. In this respect crop load control, which is used to improve fruit size, was also an important factor in altering fruit DMC, thereby affecting firmness at harvest and after storage. Furthermore, the effects of DMC on fruit firmness were independent of fruit size.     

马铃薯LK99干物质及养分累积规律研究

通过播前常规施肥、大中微量元素配施(综合养分)处理,研究其对中早熟马铃薯LK99干物质积累,N、P、K、Fe、Zn、Ca的积累、分配等的影响。研究结果表明,大中微量元素配施可明显提高LK99商品薯率和鲜薯产量,随着生育期的推进,LK99植株干物质积累量呈现"慢-快-慢"的"S"形变化规律,而干物质积累速率呈现单峰曲线变化。整个生育期LK99植株对6种养分的吸收呈"慢-快-慢"的单峰变化曲线。养分在各器官中的分配随着生长发育各阶段的推进而变化,生育前期主要分配在叶片和茎秆中,块茎形成以后,随着库的扩大,开始由茎叶向块茎运移。至成熟期,约有90%的N、P、K和80%的Zn是贮存在块茎中。大中微量元素配合施用有利于Fe、Ca在块茎中的贮存。     

长期轮作与施肥对马铃薯土壤养分和产量的影响

为探明长期轮作与施肥对马铃薯土壤养分和产量的影响,采用随机区组设计,研究了9 a(年)间不同肥料配比对马铃薯与杂粮轮作土壤养分含量的影响。结果表明,经过9 a轮作与施肥,磷钾肥区旱作土壤有机质含量从2011年的6.46 g·kg^-1上升到2019年的11.79 g·kg^-1,土壤速效养分含量总体呈现出缓慢递增的趋势,全量养分含量呈递增-降低-递增-降低的“M”态势,不同氮磷钾肥配比对马铃薯增产效果显著,在2019年产量达到最高,为12015 kg·hm-2。综上所述,经过9 a的长期轮作与施肥后,土壤质量明显提高。     

Influence of ventilation and sucrose on growth and leaf anatomy of micropropagated potato plantlets

Potato single nodes were cultured in vessels containing MS medium supplemented with 10, 20 and 30 g/l of sucrose. Vessels were closed with a clear polypropylene lid with or without 10 mm microporous polypropylene membrane. Sucrose concentration significantly increased plantlet height, shoot fresh weight and chlorophyll a content. Plantlets grown in ventilated vessels were significantly shorter, had lower shoot fresh weight and higher shoot dry weight than those in non-ventilated vessels. The highest leaf chlorophyll a content (21.83 mg/g fresh weight) was found in plantlets grown in ventilated vessels using MS medium with 20 g/l of sucrose, whereas those grown on medium with 10 g/l of sucrose had the highest chlorophyll b content (24.00 mg/g fresh weight). Total chlorophyll content was significantly higher when plantlets were grown in ventilated vessels containing medium with 10 or 30 g/l sucrose than in non-ventilated vessels. There was no significant difference in total chlorophyll content among plantlets grown in ventilated vessels with different concentrations of sucrose. Stomatal density was significantly lower when plants were grown under ventilated conditions. Leaf replica examination showed that stomata under non-ventilated condition were spherical with wide openings whereas, those in ventilated vessels were elliptical with narrow openings. Plantlets grown in non-ventilated vessels had thinner leaves and failed to build up a distinct defined upper epidermis, palisade parenchyma layer and spongy cells. On the other hand, leaves under ventilated conditions showed comparatively well organized layers with small intercellular space. The vascular system of leaves under the ventilated conditions demonstrated very well developed xylem unlike leaves under non-ventilated conditions. Thus, ventilated vessels with the 20 g/l of sucrose under ambient CO₂ in the growth room could successfully promote photomixotrophic culture and produce healthy plantlets.     

果园土壤有机质含量影响因素及提升管理策略

土壤有机质含量是衡量果园肥力水平的指标之一。由于我国果园建园选址多为贫瘠的荒山地及丘陵地,加之一些不当的传统耕作模式,致使果园土壤有机质含量低下,平均不足1%,这是制约果园生产发展的重要因素。综述了果园土壤有机质含量的影响因素及几种常见的维持或提高果园土壤有机质的管理策略,以期为提升果园土壤有机质含量,实现果园提质增效,确保果园优质丰产提供理论依据。     

胶冻样类芽孢杆菌对不同施肥处理的马铃薯产量和品质的影响

以‘克新1号’马铃薯为试验材料,试验设置低、中、高3个施肥量处理,在复合肥和有机肥的基础上,每个处理中固体胶冻样类芽孢杆菌微生物菌剂设置4个不同的梯度处理,在马铃薯块茎膨大期冲施定量的液体胶冻样类芽孢杆菌微生物菌剂,探究增施胶冻样类芽孢杆菌微生物菌剂对马铃薯生长指标、产量、品质及经济效益等的影响,旨在找出适合蒲县当地的科学施肥方法,为其马铃薯的高产优质生产提供理论和生产实践依据。结果表明,适量增施微生物菌剂有利于提高马铃薯产量、品质和经济效益等指标,但高浓度的微生物菌剂却抑制马铃薯的生长,在本试验中以低肥量处理下的T2组效果最佳,其株高、出苗率、维生素C含量、产量及净利润比常规施肥组分别提高了6.83%、5.31%、92.11%、27.0%和16.94%,还原糖含量降低了18.42%,是高产优质马铃薯的科学施肥配方及标准化生产技术方案。     

Plasticity and stability in the major fatty acid content of almond kernels grown under two Mediterranean climates

Summary

Oil contents and fatty acid compositions were determined in 17 almond cultivars growing under two different Mediterranean conditions, in northeast Spain and in central Morocco. The major differences were irrigation management in Spain and higher temperatures in Morocco. Although a cultivar effect was observed for some compounds, the general trend was for an increase in total oil content [58.65% vs. 55.58% (w/w)] and in the percentage of oleic acid [71.1% vs. 68.62% (w/w)] in those kernels harvested in Spain, probably due to having lower temperatures and better water status. As the total oil content and level of oleic acid in almond oil are the major parameters for higher quality almond kernels, these results emphasise the need to optimise the management of almond orchards to improve kernel quality, not only from the commercial and industrial points of view, but also because of their healthgiving properties.     

日光温室不同矮蔓型西葫芦的干物质生产与分配研究

对4个不同矮蔓型西葫芦品种的干物质生产与分配进行研究,结果表明,半矮蔓与矮蔓西葫芦品种各器官干物质含量没有显著差异,根、茎、叶、果干物质含量分别为:9%、6%、12%、5%;全生育期群体生长率(cropgrowth rate,CGR)半矮蔓品种平均为17.2g/(m2·d),而矮蔓品种为12.5g/(m2·d),半矮蔓品种是矮蔓品种的1.38倍;苗期、结果初期、结果中期、结果后期的当前干物质生产量半矮蔓品种分别是矮蔓品种的1.07、1.28、1.26、1.91倍,后期干物质生产衰减与矮蔓品种的早衰存在着相互依存关系;当前干物质的分配率营养器官与生殖器官的比半矮蔓品种为2.7∶1,矮蔓品种为2.1∶1;干物质累积值半矮蔓品种是矮蔓品种的1.4倍,果实干质量累积值半矮蔓品种是矮蔓品种的1.27倍,半矮蔓品种干物质向果实的分配率约为30.8%,矮蔓品种约为34.7%,单位面积干物质生产量的提高是半矮蔓品种果实干质量高于矮蔓品种的主要原因。     

虎奶菇菌核和子实体微量元素及氨基酸分析

虎奶菇子实体和菌核微量元素及氨基酸差异分析结果表明,子实体氨基酸总量为１４．７９７２％,其中必需氨基酸占氨基酸总量的４９．２１％;而菌核的氨基酸总量为１１．６７３６％,必需氨基酸占氨基酸总量的５４．０８％。子实体中微量元素Ｋ、Ｐ、Ｎａ、Ｃａ、Ｍｇ、Ｍｎ、Ｆｅ、Ｃｕ、Ｚｎ的含量比菌核分别高１２０．５０％、９５．１９％、１０４．５４％、９０．６２％、５５．７７％、４５．４０％、１９．２６％、２２２．９     

葡萄枝条堆肥化过程中的生物化学变化和物质转化特征

以葡萄枝条为原料,采用好氧静态堆肥箱法(体积为0.25 m3),分别在添加无机N素和不添加无机N素条件 下进行为期122 d的堆肥实验,结合常规化学分析、感应耦合等离子体发射光谱分析(ICPAES)和傅里叶变换红外光 谱(FTIR)分析技术研究了其堆肥化进程中的生物化学变化和物质转化特征。结果表明:添加无机N素和不加无机N 素处理的材料最高温度分别在堆肥后3 d和4 d达到76℃和65℃,堆肥高温(≥50℃)持续时间分别为21 d和7 d。干 物质变化明显分为初期(0-30 d)的快速分解阶段和中后期(30-122 d)的缓慢分解阶段,添加无机N素处理的分解速 度快于不加无机N素的。全C、全N及C/N不断下降,但全N相对含量上升,以添加无机N素处理最为明显。在整个 堆肥过程中,OH、CH3和CH2基化合物相对减少,CO基化合物相对增加,COO化合物以羧酸盐、PO化合物以磷酸盐 的形式出现。标志着脂肪族化合物减少,芳香族化合物增加以及有机物发生了明显的矿化作用。添加无机N素比不 加无机N素能更快地获得成熟稳定和富含作物所需营养的优质生态有机肥或土壤改良剂。     

糖代谢相关酶和GA_3、ABA在嫁接伽师瓜果实糖分积累中的作用

在不同发育时期测定了嫁接伽师瓜果实中蔗糖、葡萄糖和果糖含量以及蔗糖代谢相关酶———酸性转化酶(AI)、中性转化酶(NI)、蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)的活性,并对果实中糖积累与酶活性和激素含量的关系进行了分析。结果表明:蔗糖代谢相关酶和激素的综合作用是影响果实糖积累的重要因子之一;嫁接伽师瓜间果实发育过程中蔗糖、葡萄糖、果糖和糖代谢酶活性变化趋势基本一致。在果实发育早期,果实中以分解酶为主,糖分积累少;发育后期以合成酶为主,糖分积累多。嫁接伽师瓜果实糖分含量与同期自根伽师瓜相比明显减少;但嫁接伽师瓜植株生育期比自根伽师瓜延迟20-28d,果实生育期延迟15-18d,此时嫁接伽师瓜果实糖分含量明显高于自根伽师瓜。嫁接伽师瓜果实中ABA和GA3含量的变化明显滞后于自根伽师瓜,砧木可能通过影响果实糖代谢相关酶活性和激素含量来影响果实中糖分积累。     

A comparison of potato seed tuber yields in beds,pots and hydroponic systems

The objective of this study was to compare potato seed tuber production of cvs. Monalisa and Agata growing in beds, pots or hydroponics, with either single or staggered harvests. All culture systems were established in plastic sheeting-covered greenhouses protected with an anti-aphid network. The beds and 3 L pots were filled with Plantmax^® substrate and placed in suspended beds. The hydroponic system utilized NFT (Nutrient film technique) and 4 m × 15 cm × 7 cm PVC tubes with a 4% slope and the fertilizers were a commercial formula. Each experiment was 4 treatments in factorial Scheme 2 × 2 with 2 cultivars (Monalisa and Agata) and 2 harvest methods (single and staggered). All three experiments were carried out in randomized design with 6 replicates and 7 plants per replicate.     

Dry matter and area partitioning,radiation interception and radiation-use efficiency in open-field bell pepper

The objective of this study was to determine some key components of a model for bell pepper growth and yield under non-limiting water and nutrient conditions using data from field trials conducted in Southern Portugal. DM partitioning, at least before fruiting, and specific area indices for leaves, stems and fruits were conservative in relation to normalized thermal time. The interception model had a good performance. It was based on the exponential extinction of radiation on the area covered by the plants, the ellipsoidal leaf-angle distribution model (X-parameter 2.48 and 2.89), and absorptivities of the leaves for PAR and NIR, 0.8 and 0.2, respectively. Radiation-use efficiency (RUE) was determined and presented in four different forms. RUE did not change substantially throughout the growing season. RUE of irrigated pepper crops grown in our experiments was around 1.6 g MJ⁻¹ of intercepted PAR. The models and parameter values presented in this study may be useful to simulate the development and growth of field-grown pepper crop.     

不同时段补光对日光温室早春茬马铃薯光合特性、产量和品质的影响

为探究日光温室早春茬马铃薯生产的补光技术,通过对马铃薯进行CK(未补光)、T1(揭帘前补光4 h)、T2(盖帘后补光4 h)处理的试验,研究不同时段补光对日光温室早春茬马铃薯光合特性、产量及品质的影响.结果表明,较未补光处理,T1、T2处理均显著提高了马铃薯叶片净光合速率、株高、茎粗、块茎产量及淀粉含量,且T1处理下块...     

Developmental and tissue-specific changes in oxidative parameters and antioxidant systems in tomato fruits grown under salt stress

In tomato plants, salt stress has been induced to improve the quality of fruit. In general, plants under salt stress produce reactive oxygen species (ROS). Plants have their own ROS scavenging systems (antioxidant systems). In tomato plants, salt-induced changes in antioxidant systems have been examined extensively in leaves and roots; however, detailed information about salt-stressed fruits is not available. We examined the salt-induced changes in the antioxidant systems of the pericarp (containing epidermis) and pulp (containing seeds, placenta, and locule) during fruit ripening. Salt treatments were applied by adding 100 mM NaCl to the nutrient solution. In the pericarp and pulp, lipid peroxidation and hydrogen peroxide content were not increased by salt stress during ripening, indicating the absence of salt-induced oxidative stress. In the pericarp, the activities of superoxide dismutase (EC 1.15.1.1) and ascorbate (ASA)–glutathione (GSH) cycle-related enzymes increased with salt stress at the turning stage. Thus, at the turning stage, the antioxidant system may contribute to the enzymatic reaction involved ASA–GSH cycle. However, during the red and over-ripe fruit stages, salt stress produces little effect on antioxidant enzymes. In addition, the concentrations of antioxidants, such as the reduced form of ASA and GSH, increased during ripening in the control fruit, but those in the salt-stressed fruit remained unchanged. Therefore, the antioxidant system may contribute to the nonenzymatic reactions such as ASA and GSH taking place during the red and over-ripe fruit stages. In contrast, in the pulp, salt stress produces little effect on antioxidants and antioxidant enzymes. These results indicate that the salt-stressed fruit has protection mechanisms against salt-induced oxidative stress during ripening in both the pericarp and pulp. Salt-induced changes in antioxidant systems differed between the pericarp and pulp.     

Evolution of organic matter and drainages in wood fibre and coconut fibre substrates

New organic substrates have been introduced in hydroponic culture in order to substitute peat, because is a non-renewable resource, and in less rockwool or perlite due to their problematical recycling. The objective of this work is to evaluate the evolution of two renewable organic substrates, wood fibre (WF) and coconut fibre (CF) throughout one cultivation cycle. Two trials were set up, one with and a second one without crop. Volume, pH and EC of the input solution and the drainage solution were measured in both trials. In the trial without crop the content of NO₃⁻, Cl⁻, (SO₄)²⁻,Ca²⁺, Mg²⁺, Na⁺, P and K⁺ was also determined. Physico-chemical characterization of the substrates was determined at the beginning and at the end of the trials. In order to know the loss of organic matter (OM), the dry matter content of the substrates was determined at the beginning and at the end of both trials. It has been observed that in both substrates retention of elements like NO₃⁻, Ca²⁺, P and Mg²⁺ occurs. In the study of the physico-chemical properties, it has been observed that the air capacity decreases considerably in both substrates in the trial with crop, especially in the CF, as well as a greater reduction of the C/N rate and percentage of OM. The data of organic matter loosed shows that in the trial with crop both substrates have lost more OM and this loss is slightly superior in CF. Therefore it is important to consider the possible retention of nutrients in the organic substrates to optimise cultivation management, as well as their degradability, which influences on the physico-chemical properties throughout the crop cycle.