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1.
Summary

Fruit development and physiological traits were evaluated in ‘Andesu’ netted melon plants grown with and without calcium. Calcium exclusion accelerated softening, alcoholic fermentation and ethylene evolution of fruit compared with those supplied with calcium, but the opposite trend occurred with sucrose accumulation. A significant difference of calcium concentrations in the fruit between treatments was observed at the developing stage of the fruit (P<0.05), but the difference became smaller as fruit matured. In the mesocarp tissue from the basal hemisphere, calcium concentrations in the NaCl soluble fraction at ripe fruit stage differed significantly (P<0.05) between calcium treatments but no significant difference was detected in the inner mesocarp of the distal hemisphere. Calcium exclusion did not lead to the development of water-soaked symptoms in the mesocarp tissue of ripe fruit. Uronic acid concentrations in ionically bound pectin fraction did not differ between calcium treatments throughout fruit development. In covalently-bound pectin fraction, however, uronic acid concentration of ripe fruit was significantly lower in calcium-excluded plants than in calcium-supplied plants (P<0.05). Our results suggest that: first, accelerated fruit softening under calcium deficient conditions might result from promoted ethylene evolution rather than from the shortage of ionically-bound calcium in cell walls, second, calcium deficient condition does not necessarily lead to water-soaked symptoms in tissue of ‘Andesu’ melon fruit.  相似文献   

2.
马齿苋(Portulaca oleracea L.)是营养价值较高的常用野生蔬菜,含有丰富的矿质元素,但目前人们对其钙养分的存在状态还缺乏认识,因此本研究对马齿苋茎和叶进行了显微观察,以了解马齿苋是否含有固定钙的草酸钙晶体以及晶体的积累特征。结果表明,马齿苋积累的草酸钙晶体,属于簇晶类型,直径为25~50μm;分布于茎的髓部和叶的叶肉组织中,叶中晶体多,每1 mm2叶片约含有287个晶体,而茎中含晶体少,每1 mm2茎横切面上只含有26多个晶体。叶中的草酸总含量、可溶性草酸和不溶性草酸含量均高于茎中,草酸分布模式与草酸钙晶体分布模式一致。显然,由于草酸钙晶体的积累,马齿苋中的钙相当一部分以难溶状态存在。  相似文献   

3.
采用石蜡切片技术对甜瓜果实发育的组织结构进行了观察。结果表明：甜瓜外果皮包括表皮、气孔器和表皮毛，在幼果生长过程中，外表皮细胞主要进行垂周分裂，以适应果实体积的增大，随着果实的逐步发育，表皮细胞间隙逐渐填充一些含有木质素成分的物质，并在表皮细胞表面形成一层较厚的角质层。中果皮分为上中果皮和下中果皮，上中果皮包括薄壁细胞和横向伸长细胞，下中果皮则主要包括海绵组织和其中的维管束。幼果期，中果皮细胞排列紧密，各部分细胞大小及形态无明显差异。随着果实的发育，细胞分裂速度减慢，细胞体积不断增大，中果皮细胞径向直径呈现出梯度变化，由外向内逐渐增大。在果实成熟过程中，下中果皮大部分细胞高度分散，细胞壁破裂，细胞互相融合。构成细胞壁的纤维素成分快速溶解，果实软化成熟。  相似文献   

4.
SUMMARY

We examined growth and development of the ‘Manzanilla’ olive fruit mesocarp in transverse equatorial sections during the first 12 weeks after full bloom (AFB). Sequential sampling and quantitative data provided an integrated view of the formation of this tissue. The mesocarp, or fruit flesh, was formed by relatively isodiametric parenchyma cells with a small number of isolated sclereids. By four weeks AFB a gradient in cell size characteristic of mature olive fruits began to appear. Biweekly measurements of cell size and number indicated that, as in other drupes, both cell division and expansion contribute to initial mesocarp growth. From six weeks AFB, further mesocarp growth was determined solely by cell expansion. Transverse areas of mesocarp and endocarp, also measured biweekly, revealed that both tissues expand in a similar manner until eight weeks AFB, after which mesocarp growth predominated.  相似文献   

5.
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   

6.
In drupe fruits, in addition to fruit size, the proportions of mesocarp and endocarp tissues are critical objectives for fruit quality, crop production and management. The olive fruit is a typical drupe, with cultivars which show a wide range in both fruit size and the proportions of mesocarp and endocarp. Characterizing the roles of tissue and cellular processes in producing genetically based fruit size variability is necessary for crop improvement, as well as deepening our understanding of fruit developmental physiology. This study used microscope image analysis to evaluate cell number and size, the growth of mesocarp and endocarp tissues, and their developmental timing in producing fruit size among six olive cultivars with a large range of fruit size. We found that cultivar mesocarp and endocarp size increased linearly with fruit size, with larger sizes favoring an increasingly greater mesocarp/endocarp ratio. Within the mesocarp, cultivar-based fruit size related directly to cell number and was established soon after bloom by cell division rate. In spite of different cell division rates, all cultivars showed similar timing of cell division activity, with the majority of cells produced in the two months after bloom but, surprisingly, a substantial number of cells formed during the following 6 months. Cell expansion was high throughout fruit growth and an important factor in achieving final fruit size, but cell size did not differ among cultivars at any time. We can conclude that fruit size differences among olive cultivars are due at the tissue level to both mesocarp and endocarp sizes and at the cellular level to cell division throughout fruit growth. Furthermore, since cell size is consistent among cultivars in spite of variable cell division, it is likely that cultivar differences in cell expansion accompany those in cell division.  相似文献   

7.
李淑久  牟君富 《园艺学报》1994,21(4):339-343
红子果实的肉质果壁是由托附杯借细胞体积增大发育而来。成熟果壁细胞不含有淀粉粒，但具有大量单宁细胞。速冻果果壁细胞间隙和细胞内有许多小冰晶体，细胞受损害小。缓冻果的胞间冰晶体大而数量少，细胞受损程度大。  相似文献   

8.
荔枝果皮的扫描电镜观察   总被引：21，自引：1，他引：20  
潘洵操  谢宝贵 《园艺学报》1996,23(3):227-230
荔枝极不耐贮，果实采收后３～４天即开始变褐、变质、霉烂。用扫描电镜技术观察查皮结构，发现其外果皮细胞外壁和角质层很薄，且向外作半球形突出，易受机械损伤，因而保护能力较差。  相似文献   

9.
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10.
 以‘黄冠’梨为材料,研究了采后热处理（38 ℃热空气24 h）,钙处理（6% CaCl2浸果15 min）及热加钙处理（6% CaCl2 + 38 ℃）对果实低温贮藏过程中钙形态及细胞壁物质代谢的影响,以清水浸果为对照。结果表明：果胶钙为果实中主要的钙形态,其含量占全钙的49.7% ~ 55.8%,钙处理、热加钙处理果实的总钙含量与对照相比分别增加了22.95和31.58 µg · g-1;钙处理、热加钙处理显著抑制了果实纤维素、原果胶、水溶性钙及果胶钙含量的下降,促进了草酸钙含量的增加,延缓了果实硬度的下降;热处理、热加钙处理显著降低了多聚半乳糖醛酸酶（PG）、果胶甲酯酶（PME）和纤维素酶活性。相关分析表明,果实硬度与纤维素、原果胶、水溶性钙和果胶钙含量呈极显著正相关,与可溶性果胶含量呈极显著负相关;PG和纤维素酶与果实硬度均呈极显著负相关,PME与果实硬度的相关性不显著。钙处理、热加钙处理通过抑制可溶性钙向难溶性钙转化、细胞壁组成成分降解以及降低细胞壁降解酶活性,延缓果实软化,其中以6% CaCl2 + 38 ℃的处理效果最好。  相似文献   

11.
Differences in mature fruit size among olive cultivars are related to differences in ovary size at bloom, but it is not known whether cell number or size determines the variation in ovary size. In this study we measured cell size and number in equatorial cross-sectional areas of the principal ovary tissues (mesocarp and endocarp) in eight cultivars with very different fruit and ovary size. The results showed that cell number explained most of the differences in ovary size, while cell size was not related to ovary size, except for a weak (R2 = 0.33) correlation in the endocarp. Since sink strength is thought to be related to cell number, this finding supports the hypothesis that larger ovaries represent stronger sinks. The implications of greater sink strength with bigger ovaries are discussed. Within cultivars, while the cross-sectional areas of mesocarp and endocarp were similar, cell number was higher in the mesocarp but cell size was smaller compared to the endocarp.  相似文献   

12.
Summary

Changes in cellulose content and the accumulation of PpCesA1 mRNA, putatively encoding the catalytic subunit of cellulose synthase (CesA), were analysed in endocarp and mesocarp during endocarp hardening in peach fruit. The cellulose content of the endocarp was undetectable or very low [< 0.1 mg g–1 fresh weight (FW) of endocarp] until 48 d after full bloom (DAFB), but began to increase rapidly at 55 DAFB, when the endocarp had attained its maximum size, and reached 4.4 mg g–1 FW of endocarp at 85 DAFB. In contrast, the cellulose content of the mesocarp reached a detectable level (1.5 mg g–1 FW of mesocarp) at 34 DAFB, stayed at this level until 85 DAFB, but then was lower at 107 DAFB. PpCesA1 mRNA was detected in the endocarp throughout the hardening, but was undetectable in the mesocarp. It is suggested that PpCesA1 has a role in the rapid synthesis of cellulose in the secondary cell walls of endocarp tissue during hardening.  相似文献   

13.
疏花对大久保桃中果皮细胞分裂与膨大的影响   总被引：3，自引：0，他引：3  
 研究了大久保桃树〔Prunus persica (L. ) Batsch. ‘Okubo’〕疏花后果实生长发育期间果皮细胞分裂与膨大的变化。结果表明: 果皮细胞分裂一直持续到盛花后6周。疏花明显促进了花后3周内幼果中果皮的细胞分裂, 增加了果实中果皮细胞层数和果皮厚度, 这是导致成熟果实体积增大的主要原因。  相似文献   

14.
Summary

Boron (B)-deficiency is a nutritional problem in the citrus industry worldwide. Under B-deficient conditions, symptoms such as corky split veins, small fruit, low tree vigour, and low fruit yield appear. In this study, we investigated the anatomical responses of mature leaves and the albedo of mature fruit of HB pummelo [Citrus grandis (L.) Osbeck] to B-deficiency. Under B-deficient conditions, the numbers of parenchyma cells in the vascular bundles of the leaf and fruit mesocarp increased significantly. The ratio of the area of the phloem to the area of the vascular bundle also increased, while the ratio of the area of the xylem to the area of the vascular bundle decreased in both tissues. Moreover, we observed alterations in the xylem elements under B-deficient conditions. The average lengths of xylem vessels were 216.7 µm and 175.4 µm in leaf main veins and in fruit mesocarp, respectively, both significantly lower than the corresponding values in B-sufficient control plants. However, B-deficiency reduced the average diameter of xylem vessels only in leaf main veins. On the other hand, B-deficiency increased the numbers of pitted vessels to 63 and 59 among 100 xylem vessels sampled at random in leaf main veins and in the fruit mesocarp of B-deficient pummelos, respectively, while the corresponding numbers were 43 and 35, respectively, under B-sufficient conditions. B-deficiency also decreased the numbers of scalariform and reticulated vessels. Possible mechanisms for these anatomical modifications under B-deficient conditions are discussed.  相似文献   

15.
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   

16.
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   

17.
The effect of increasing fruit maturity on fruit base mineral composition, phenolic content and the resultant influence on postharvest fruit quality and ripening physiology of ‘Fuerte’ avocado was investigated. Late harvested fruit with increasing maturity had reduced calcium and magnesium concentrations. A reduction in ripening time was associated with a decrease in fruit calcium concentration. The relationship, if any, between fruit potassium concentration and relative maturity was less clear. Total fruit phenolics increased with increasing fruit maturity and this was associated with an increased incidence of the cold storage browning disorder, mesocarp discoloration. Cold storage had no effect on total fruit phenolic concentration.  相似文献   

18.
灵武长枣正常果与裂果解剖结构的比较研究   总被引：5，自引：0，他引：5  
运用石蜡切片对灵武长枣正常果实与裂果的解剖结构进行了观察,探讨裂果发生的原因。结果表明:长枣正常果角质层厚度、亚表皮细胞层数与裂果相近;但正常果实表皮细胞层数较裂果多,表皮厚度也较裂果厚;中果皮细胞排列较裂果的紧密;中果皮细胞大小、维管束粗细及多少、空腔大小及多少与裂果的相近。  相似文献   

19.
Phospholipase D, the key enzyme involved in membrane phospholipid catabolism, was localized in strawberry (Fragaria ananassa Duch.) fruits during development using immunohistochemical techniques. Typical structural features such as the nucleus, cell wall, plasma membrane, mitochondria and vacuole were noticeable in cells of young strawberry fruits. Cytoplasmic structural features were less pronounced in fully grown and turning red fruits, except cell wall, which was considerably enlarged. Also, extensive microvesiculation from the plasma membrane was noticeable in ripening fruits. The number of visible gold particles indicative of phospholipase D increased during development. Phospholipase D was found to be associated with membranous structures and vacuole. Interestingly, gold-particles could also be observed in the cell wall space in ripening fruits suggesting that cytosolic contents may have leaked into the cell wall space as a result of membrane deterioration and loss of compartmentalization. The role of phospholipase D during development and ripening of strawberry, a non-climacteric fruit, is discussed.  相似文献   

20.
 研究了野生欧李萌动期、开花期和果实发育期各组织器官中不同形态钙含量的变化及其相关性。结果表明,野生欧李对钙的吸收积累与钙的形态密切相关,木质部和花器官、果实、果柄中的钙主要以果胶钙形态为主,韧皮部和新梢中的钙主要以草酸钙形态为主。在年生长发育时期,木质部中各种形态钙含量总体呈下降趋势,进入果实成熟膨大期含量回升;韧皮部中各种形态钙含量总体呈下降趋势,进入果实成熟膨大期水溶钙、果胶钙、磷酸钙和草酸钙含量略有回升;花器官和果实中各种形态钙含量变化呈“下降—增加（或下降）—下降”的变化;在果实发育期,新梢中的水溶钙、果胶钙、草酸钙和剩余钙含量明显增加,而果柄中的水溶钙含量增加最为明显。随生长发育进程各组织器官中存在钙形态转化。木质部、韧皮部、花和果实中水溶钙和果胶钙含量的年变化与相应器官中钙总量之间存在高度正相关。  相似文献   

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