首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 809 毫秒
1.
Summary

The cracking of bell pepper fruit is one of the main physiological disorders that reduce marketable yield. Understanding the environmental and endogenous factors that influence this disorder may help to reduce its severity. Plants grown in three greenhouses were subjected to differing potential transpiration (Tp) at night, with identical daytime Tp. Measurements included climatic variables in the greenhouses, soil water content, sap flow, transpiration, leaf temperature, surface and internal fruit temperatures, fruit and stem diameters, stomatal conductance, and leaf area. The results show that at night pepper plants transpired at a rate proportional to the vapour pressure difference (leaves to air; VDPla) in the respective greenhouses. The percentage of cracked fruits was highest in the greenhouse with the lowest night vapour pressure deficit (VPD) and lowest in the greenhouse with the highest VPD. Both increased direct radiation reaching the fruit surface and decreased soil water content reduced the growth rate of the fruit. Direct radiation and the temperature of the fruit inner space were well correlated with diurnal expansion and shrinkage of the fruit. The fruits with the higher expansion-shrinkage amplitude had more severe cracking symptoms. Decreased soil water potential counteracted the negative effect of direct radiation. These results indicate that the water status of the fruit is a key factor in determining the severity of fruit cracking. The implications of these results for greenhouse management in pepper production are discussed.  相似文献   

2.
SUMMARY

“Colour spots” (CS) in pepper fruit is a physiological disorder characteristic of some sweet pepper cultivars. The symptoms are yellowish spots on the outer surface of affected fruits. We investigated the effects of shading and nitrogen supply on the susceptibility of three sweet pepper cvs (Maor, Lady Bell and 899) to CS. The most susceptible was ‘Maor’. The incidence of CS was promoted by high N and shading. The fruits of all cultivars had lower nitrogen concentrations than the leaves but there were no significant differences in fruit N content between Maor and the CS-insensitive cultivars. The CS-affected areas of the pericarp tissue had higher calcium concentrations than unaffected tissue. Differences in magnesium or potassium concentrations in these spots were less pronounced. Scanning electron microscopy revealed that the affected pericarp cells contained crystals, presumably of calcium oxalate. Only in ‘Maor’ fruits was the oxalate concentration elevated by approximately nine-fold when the nitrogen supply to shaded plants was increased. We suggest that in the fruits of the sensitive cultivar, oxalic acid production is enhanced under high-nitrogen + shading conditions and causes the CS damage, possibly be chelating intracellular calcium.  相似文献   

3.
SUMMARY

Heat stress causes abscission of flowers in pepper plants and thus reduces yield. In the present study, we investigated the involvement of ethylene in heat-stress related flower abscission, by comparing the response of flowers of bell pepper, cv. Maor, known to be sensitive to flower abscission, and flowers of paprika, cv. Lehava, a resistant cultivar of Capsicum annuum. Their differing susceptibilities to high temperatures depend on light. Under high-temperature, high-light conditions, bell pepper was less susceptible than paprika, but, under high-temperature low-light, bell pepper was more susceptible. At high temperatures, flower explant abscission was much higher with bell pepper than paprika. Ethylene production (EP) by bell pepper explants reached a maximum at 34°C and decreased at higher temperatures (42 and 48 C), while in paprika EP rates were lower and reached the maximum at 42°C. Explants of bell pepper flowers were more susceptible to exogenous ethephon than paprika flowers. The sensitivity of a collection of pepper cul-tivars to heat induced flower abscission was more closely correlated with their flower sensitivity to ethephon than with the flower EP rate. We suggest that the differential susceptibility of bell pepper and paprika to heat stress is a result of both different ethylene production by their flowers and their differing sensitivities to ethylene produced under high-temperature stress. However, the sensitivity of the flower to ethylene may be more important in inducing their abscission.  相似文献   

4.
Summary

The aim of the present research was to study changes in the major anti-oxidative enzyme activities known to be associated with the apoplast, during the induction of blossom-end rot (BER) in bell pepper (Capsicum annuum L.) fruits grown under saline conditions. Pepper plants of the BER-sensitive cv. ‘Mazurka’ and less-sensitive cv. ‘Selica’ were grown under control, low- and high-salinity irrigation regimes. Fruits were harvested continuously and, after approx. 7 months under these conditions, BER symptoms started to appear (in the Spring season) and fruits were sampled for biochemical measurements. The intercellular washing fluid (IWF; apoplast fraction) of the fruit pericarp was prepared and enzyme activities in that fraction were determined. The results showed that production of reactive oxygen species (ROS) in the fruit apoplast was higher in ‘Mazurka’ than in ‘Selica’. Apoplastic peroxidase and superoxide dismutase (SOD) activities, and the concentration of ascorbic acid, increased during ‘Selica’ fruit development, whereas the concentration of H2O2 decreased. During the stage of rapid growth, when fruits are most susceptible to BER, apoplastic peroxidase activity was greatly enhanced in the healthy pericarp of BER-affected fruits compared to healthy fruits. Under saline conditions, apoplastic peroxidase and SOD activities, as well as ascorbic acid and H2O2 levels, increased in healthy fruits of the resistant cultivar ‘Selica’; whereas, in healthy fruit of the BER-sensitive cultivar ‘Mazurka’, apoplastic peroxidase activity decreased while the level of ascorbic acid increased, but to a much lesser extent than in ‘Selica’. SOD activity and H2O2 levels increased similarly in both cultivars with increasing levels of salinity. It is proposed that apoplast-associated peroxidase activity and ascorbic acid concentration are increased coordinately in response to salt stress and may be part of a protective anti-oxidation mechanism that determines cultivar sensitivity to BER.  相似文献   

5.
This work was carried out to study the effects of two soilless media consisting of 80:20 [volume/volume (v/v)] mixtures of mosspeat and perlite, or cocopeat and perlite, on fruit quality and anti-oxidant activities in four cultivars of bell pepper (Capsicum annuum L.): ‘Traviata’ (green), ‘Inspratian’ (red), ‘Aracia’ (orange), and ‘Taranto’ (yellow). The results showed that the composition of the medium had a significant effect on the anti-oxidant composition and activities of the bell pepper fruit. Plants grown on 80:20 (v/v) mosspeat and perlite had significantly higher pericarp firmness, titratable acidity, total phenolic compound concentrations, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability, and the hydroxy free-radical (?OH) scavenging ability. Fruit on plants grown on 80:20 (v/v) cocopeat and perlite had significantly higher vitamin C concentrations. Among the four cultivars tested, ‘Inspratian’ (red) was superior in more factors including pericarp thickness, dry matter content, titratable acidity, total soluble solids content, total phenolic concentration, DPPH scavenging ability, and vitamin C concentration. There was a significant interaction between cultivar and soilless medium composition, indicating that the response of bell pepper cultivars varied in the different media. The results of the present study highlight the importance of comparing soilless media in terms of their effect on fruit crop quality and anti-oxidant activity.  相似文献   

6.
Summary

The main goal of this research was to investigate the effects of a wet pad-and-fan evaporative cooling system (ECS) on the incidence of blossom-end rot (BER) and fruit cracking in greenhouse-grown bell pepper (Capsicum annuum L.). The specific objectives were: (i) to study the efficiency of the wet pad-and-fan ECS in improving plant water status and reducing transpiration; and (ii) to explore the impact of these conditions on fruit yield, fruit Ca content and the incidence of BER and fruit cracking. For 3 years, peppers were grown in the Lachish Region, Israel, in a greenhouse divided into two compartments, one with and one without (control) a pad-and-fan ECS. The results showed that the ECS increased total fruit yield and the incidence of cracked fruits, but reduced the incidence of BER. The efficiency of the ECS in reducing temperature and vapour pressure deficit (VPD) decreased as the distance from the wet pad increased. Consequently, the incidence of cracked fruits decreased with distance from the wet pad, whereas the incidence of BER increased.  相似文献   

7.
冬枣与临猗梨枣杂交子代果实裂果特性研究   总被引：1，自引：0，他引：1  
 研究影响枣裂果的因素对选育抗裂果品种和开发防裂措施具有重要意义。对冬枣 × 临猗梨 枣的F1 子代分离群体进行裂果率和裂果指数测定,并进行石蜡制片和显微观测,探讨同一分离群体的不 同基因型个体间成熟果实表皮结构与裂果的关系。结果显示,48-LS-33,47-LS-22,II-13-15 为极抗裂株 系;抗裂株系比易裂株系果实表皮厚,果实表皮厚度和裂果率呈显著负相关,抗裂类型果实表皮细胞排 列较紧密,角质层沉积导致的表皮第一层细胞垂周状变化明显,而角质层厚度与裂果无明显相关性。  相似文献   

8.
《Scientia Horticulturae》2005,103(2):249-255
Bromeliad growers report severe leaf quality problems for Aechmea cultivars grown under commercial greenhouse conditions. In this research, a leaf damage ‘sensitive’ and ‘insensitive’ A. cultivar were compared for their C-metabolism and hydrophysiology under these greenhouse conditions. Stomata opening index indicated CAM (Crassulacean acid metabolism) for both cultivars, with 45–50% open stomata around 4:00 a.m. and 5–10% in the afternoon. Malic and citric acid were the major organic acids present in the leaves, with diurnal malic acid accumulation during the night. The leaf damage ‘sensitive’ cultivar showed higher malic acid accumulation than the ‘insensitive’ cultivar (200 μmol/gfw versus 170 μmol/gfw). Leaf osmotic potential and turgor pressure were linked with diurnal malic acid fluctuations: organic acid accumulation during the night generated high leaf turgor pressures (up to +0.86 MPa).A leaf damage sensitivity test was designed and confirmed previous experiences of several bromeliad growers. Both cultivars showed higher leaf damage percentages (98 and 78%) when leaf malic acid accumulation was high. We attribute this elevated sensitivity to lethal turgor pressures and consider them to be caused by the water capturing mechanism generated by high organic acid accumulation. Under current greenhouse conditions, this water capturing mechanism can be disastrous for plant leaf quality. Especially, under high relative humidity, hindering plant transpiration and stimulating water uptake by dew formation, leaf quality could be endangered.  相似文献   

9.
Calcium in different forms was compared in the pericarp of cracked and healthy fruit in the cracking-susceptible litchi (Litchi chinensis Sonn.) cultivar ‘Nuomici’. Incorporation of 45Ca into the cell walls of the pericarp and effects of sprays of calcium chloride (0.2% or 0.5%) on endogenous calcium and cracking incidence were examined. The results showed that calcium concentration in cracked fruit was significantly lower than in healthy fruit. Structural calcium as part of cell wall components contributed to the majority of the difference in calcium concentration between cracked fruit and healthy fruit. Surface spray of calcium chloride, either once or three times at different stages of fruit development exhibited no significant effect on fruit cracking and hardly increased calcium, especially structural calcium in the pericarp. X-ray microanalysis revealed that the applied calcium remained on pericarp surface. Radioisotope test showed that less than 0.1% of 45Ca applied on fruit surface was incorporated into the cell walls. It is suggested that spraying calcium on fruit surface is not an effective way to prevent litchi fruit cracking due to the difficulty in uptake of the calcium sprayed on fruit surface.  相似文献   

10.
Summary

Fruit of Cereus peruvianus (L.) Miller, a newly developed cactus crop, is subject to cracking. Fruit growth follows a double sigmoid curve, with a significant size increase in the first and third stages and moderate increase in the middle stage. Peel and seed grow in the first two stages, while pulp growth and maturation (e.g. peel colour change and stretching, sugar accumulation, fruit softening) occur in the final stage. Sensitive, moderately sensitive, and tolerant clones are subject to 100, 50–60 and 6–9% cracking, respectively, correlated to relative growth rate of the pulp in the third stage. Fruit cracking, lengthwise splitting of the peel, and exposure of the pulp occurred in fully mature fruits towards the end of their growth. Continuous monitoring of fruit growth revealed expansion and cracking during the day and shrinkage during the night, as expected for CAM plants. Cracking was not correlated with the threshold cracking turgor, which declined during ripening in all clones. GA3 sprays during colour break reduced cracking in the two most susceptible clones to 20% and 60%, while paclobutrazol increased cracking. Cracking rates were the same in two ecozones differing in salinity, temperatures and relative humidity. It is suggested that breeding and hormone treatments could reduce cracking significantly.  相似文献   

11.
Fruit development was investigated in field and changes in pericarp structure were comparatively studied in over-winter off-season and on-season longan (Dimocarpus longan Lour. cv. Chuliang). The results showed developmental problems including small fruit size, severe fruit cracking and heavy fruit drop in the off-season fruit, although their seed size was not significantly affected compared to the on-season fruit. Anatomical studies showed that off-season longan fruit had a poorly developed pericarp, which was reflected by smaller fresh weight as well as thinner pericarp thickness, thinner spongy tissue, fewer cell layers in the periderm, smaller cell size and fewer cell numbers in the parenchyma tissue at the upper mesocarp, and fewer cell layers in the endocarp. In contrast, the recovery of the sclereids in the mesocarp was higher in the pericarp of the off-season fruit. The poor development of the pericarp in off-season fruit probably caused the small fruit size and severe fruit cracking. It was suggested that the adverse climatic conditions encountered by fruit development in the over-winter off-season longan suppressed cell division and expansion in the pericarp but did not affect sclereid formation.  相似文献   

12.
  相似文献   

13.
抗裂与易裂枣内源激素含量和细胞壁代谢相关酶活性比较   总被引：4，自引：0，他引：4  
 以枣抗裂果品种‘圆铃枣’和易裂果品种‘俊枣’为材料,测定了果实生长发育曲线、果 形指数及种子败育率,并对果皮、果肉、种子中内源激素含量及果皮、果肉中细胞壁代谢相关酶的活性 进行了检测。结果表明,‘俊枣’果形指数和种子败育率均显著高于‘圆铃枣’。果实发育后期‘俊枣’ 果皮中的GA3 含量、果肉中的IAA 含量明显高于‘圆铃枣’,而‘圆铃枣’果肉及种子中的ABA 含量高 于‘俊枣’;‘俊枣’果肉及种子中（GA3 + IAA + ZT）/ABA 的比值在整个果实生长发育期均高于‘圆铃 枣’。果实生长发育后期‘俊枣’果皮中的果胶酶及纤维素酶活性高于‘圆铃枣’,且‘俊枣’果肉中的 POD 及PPO 活性也较高。以上结果显示,枣果实生长发育后期易裂品种‘俊枣’果肉中的IAA 积累较多, 而抗裂品种‘圆铃枣’果肉及种子中ABA 含量显著高于易裂品种;易裂品种‘俊枣’果肉及种子中（GA3 + IAA + ZT）/ABA 的比值较高,果皮中的果胶酶、纤维素酶活性影响裂果的发生,其POD 及PPO 活性相 对较高。  相似文献   

14.
为了探讨贵州地方辣椒品种资源的类别、分布与开发利用情况,在对贵州地方辣椒资源的收集调查整理的基础上,依据目前通行的分类标准,将贵州辣椒分为一年生栽培种(Capsicum annuum L.)和多年生栽培种(C.frutescens L.);以果形、果色、果实着生方向和栽培性状为依据,将贵州辣椒分为锥形椒、指形椒、牛角椒、线椒、灯笼椒、樱桃椒、簇生椒、黄辣椒、小山椒共9个类型;依据辣椒类型在某个区域范围内的栽培比例达70%为标准,将贵州辣椒资源划分为5个集中分布区,即牛角椒集中分布区,朝天椒集中分布区,线椒、牛角椒集中分布区,线椒、簇生朝天椒集中分布区,朝天椒、小山椒集中分布区;分析认为,贵州辣椒地方资源的综合开发应用潜力较大。  相似文献   

15.
 ‘井岗红糯’是由荔枝实生树中选出的优良品种。果实心形,果皮鲜红,平均单果质量23.5 g;平均果皮厚度1.62 mm,抗裂果,果肉厚,味清甜,有‘糯米糍’的风味及‘桂味’的肉质,可溶性固形物20.0%,可食率77.3%,焦核率80%。生长势强,晚熟,较抗荔枝霜疫霉病。  相似文献   

16.
‘武农8号’是早熟小果型西瓜杂交一代新品种。植株长势强健,易坐果。果实膨大快,单果质量1.43 ~ 2.06 kg。果实椭圆形,果皮绿色,覆墨绿色齿条,厚度0.54 cm,蜡粉轻;果肉红色,中心糖含量12.5%,边糖含量10%,肉质松脆细嫩,品质佳,耐裂。生育期95 d,果实发育期27 ~ 31 d,适合湖北春播日光温室和塑料大棚早熟覆盖栽培。  相似文献   

17.
‘红宝石’是从福建省邵武市将石自然保护区野生圆齿野鸦椿中选育出的新品种。果实成熟期早,果皮厚实,成熟果实的果皮开裂前外果皮赤红无瑕,裂成二瓣后呈蝴蝶翅状。挂果期为7月至次年2月。可在圆齿野鸦椿分布范围推广应用。  相似文献   

18.
为了提高彩椒坐果率和降低畸形果率,以彩椒品种世季红为试材,研究3种配方保花保果剂对彩椒产量、坐果数和商品果率的影响,并在低温弱光照、亚适温弱光照和高温条件下比较最优配方在朝天椒、线椒和牛角椒上的应用效果。结果表明,喷施配方P_2(A液:复硝酚钠0.03 g·m L~(-1),B液:赤霉素0.10 g·m L~(-1)、2,4-D钠盐0.01 g·m L~(-1)、萘乙酸钠盐0.10g·m L~(-1))对彩椒保花保果效果最佳,小区产量、坐果数均显著高于对照,且商品果率和单果质量与对照无显著差异。在逆境条件下不同类型辣椒喷施配方P_2后,小区产量和坐果数均显著提高,商品果率和单果质量与对照无显著差异。综上,配方P_2能解决甜(辣)椒畸形果率与坐果率的矛盾且稳定性好,不同类型辣椒品种在不同逆境下均可应用配方P_2进行保花保果。  相似文献   

19.
荔枝果皮对外源钙和蔗糖吸收及向细胞壁沉着的研究   总被引：6，自引：0，他引：6  
利用放射性同位素示踪技术研究荔枝果皮对外源钙和蔗糖的吸收及细胞壁构建规律。结果表明,进入果皮的蔗糖主要被用以构建细胞壁,但随果实发育,蔗糖用于构建细胞壁比例减少,更多分布于果皮组织的可溶性成分中;果梗向果实运输钙的效率远远低于蔗糖运输效率;NAA处理果实短期内可明显促进蔗糖向果实运输,但不能促进果梗的钙进入果实,说明蔗糖和钙向果实运输有不同调控机制;施于果实表面的钙虽可被吸收并成为细胞壁的结构钙,但比例不到千分之一;硝酸(根)离子和NAA可一定程度促进外源钙向细胞壁沉着;抗裂的怀枝果皮细胞壁的钙含量比易裂的糯米糍高,其细胞壁结合外源钙的能力也强于后者,说明前者细胞壁中果胶半乳糖醛酸残基含量高于后者,也是怀枝具有较强抗裂性的物质基础之一;2品种14C-蔗糖向果皮细胞壁沉着均在果实发育初期最活跃,怀枝细胞壁构建也只是在果实发育初期比糯米糍更活跃,这就意味着抗裂性形成的关键时期是在果皮发育的初期。  相似文献   

20.
龙眼果皮发育解剖学观察   总被引：1，自引：0，他引：1  
以储良龙眼品种为试材,观察了果皮的解剖结构发育特点。果皮发育早期(花后10d前),细胞体积小,排列紧密,细胞分裂活跃,外果皮有凸起的皱褶结构,有大量的表皮毛分化。果皮发育中期(花后10～52d),细胞体积变大,表皮毛开始脱落,外果皮逐渐平滑,中果皮处有石细胞群和海绵状组织的分化。果实发育后期(花后52d后,假种皮快速膨大阶段),有木栓形成层出现,形成周皮代替表皮起保护作用,随着果实生长,木栓层出现局部破裂。龙眼果皮可划分为外、中、内3层。中外果皮在发生次生木栓化前,由外表皮细胞及其附属物和角质层组成;在形成木栓形成层产生次生结构后,外果皮则由周皮组成。内果皮来源于子房内壁的几层细胞,由一层内表皮细胞和与之紧密相连的几层薄壁细胞组成。中果皮根据其组织特点可进一步分为上中果皮和下中果皮,上中果皮包括石细胞群、外层维管束和外果皮之内的薄壁细胞;下中果皮则主要包括海绵组织和其中的维管束。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号