Fruit Development Period Research Articles

Southern highbush blueberry responses to humic acid application in soilless substrates

Humic acids are a biostimulant that has captured the interest of blueberry growers, but information about humic acid use in blueberry is scarce. Blueberry plants suffer water deficit stress during transplant and photosynthetic limitations during fruit development. We hypothesized that humic acid applications improve transplant success and increase fruit yield and quality in southern highbush blueberry (SHB, Vaccinium corymbosum interspecific hybrids) grown in soilless substrates. We tested these hypotheses in two greenhouse experiments. First, we grew ‘Sweetcrisp’ SHB in rhizoboxes. Humic acids were applied via drench at concentrations of 0 mL⋅L−1, 7 mL⋅L−1, 13 mL⋅L−1, and 24 mL⋅L−1 for 10 weeks. Humic acid application increased substrate respiration rates, pH, and electrical conductivity, but they did not increase root growth or improved transplant success. In a separate experiment, one year-old plants of ‘Avanti’, FL 09-311, and FL 06-19 SHB plants in 1.7 L pots were treated with 0 mL⋅L−1, 13 mL⋅L−1, and 24 mL⋅L−1 humic acids during the fruit development period. Humic acid application did not increase yields and occasionally reduced fruit quality. While plant responses were genotype specific, these results suggest that humic acid applications are not beneficial during the transplant or fruit development periods in substrate-grown blueberry.

SlGH9-15 regulates tomato fruit cracking with hormonal and abiotic stress responsiveness cis-elements

Fruit cracking occurs easily during the late period of fruit development when plants encounter an unsuitable environment, dramatically affecting fruit production and marketing. This study conducted the bulked segregant RNA-Seq (BSR) to identify the key regulatory gene of fruit cracking in tomatoes. BSR-Seq analysis illustrated that two regions associated with irregularly cracking were located on chromosomes 9 and 11, containing 127 candidate genes. Further, through differentially expression analysis and qRT-PCR in cracking-susceptible and cracking-resistant genotypes, the candidate gene SlGH9-15 (Solyc09g010210) with significantly differential expression levels was screened. Bioinformatics analysis of the GH9 gene family revealed that 20 SlGH9 genes were divided into three groups. The phylogenetic analysis showed that SlGH9-15 was closely related to cell wall construction-associated genes AtGH9B1, AtGH9B6, OsGH9B1, and OsGH9B3. The cis-acting elements analysis revealed that SlGH9-15 was activated by various hormones (ethylene and ABA) and abiotic stresses. The expression pattern indicated that 13 SlGH9 genes, especially SlGH9-15, were highly expressed in the cracking-susceptible genotype. Its expression level gradually increased during fruit development and achieved maximum value at the red ripe stage. Additionally, the cracking-susceptible tomato showed higher cellulase activity and lower cellulose content than the cracking-resistant tomato, particularly at the red ripe stage. This study identified SlGH9-15 as a key gene associated with fruit cracking in tomatoes for the first time and gives new insights for understanding the molecular mechanism and complex regulatory network of fruit cracking.

The Molecular Markers Associated with Fruit Development Period in ‘Yumyeong’ Peach Cultivars

The Molecular Markers Associated with Fruit Development Period in ‘Yumyeong’ Peach Cultivars

Climate warming leads to advanced fruit development period of temperate woody species but divergent changes in its length.

Climate warming has significantly altered the phenology of plants in recent decades. However, in contrast to the widely reported warming-induced extension of vegetative growing season, the response of fruit development period (FDP) from flowering to fruiting remains largely unexplored, particularly for woody plants. Analyzing >560,000 in situ observations of both flowering and fruiting dates for six temperate woody species across 2958 European phenological observations sites during 1980-2013, we found that in all species both flowering and fruiting phenology, that is, the FDP, advanced with climate warming. However, the advancing rates of the two events were not necessarily equal for any given species, resulting in divergent changes in the length of FDP among species with climate warming. During 1980-2013, not only the temperature during FDP but also the forcing requirement for fruit development increased, both affecting the length of FDP. The shortened FDP was mainly due to elevated temperature, thus accelerating the accumulation of forcing, whereas the prolonged FDP was primarily caused by the substantial increase of the forcing requirement of fruiting, which could be fulfilled only in a longer time and thus slowed down the advance of fruiting. This study provides large-scale empirical evidence of warming-induced advances of FDP but divergent changes in its length in temperate woody species. Our findings demonstrate the contrasting reproductive phenological strategies among temperate woody species under the pressure of warming climate, contrary to the lengthening of vegetative growing season, which is by and largely similar with different woody species.

Morphogenesis of fruit as a subject matter for the carpological studies

In this review, the concept of fruit morphogenesis is treated in the context of implementation of the evo-devo approach in carpology. A new viewpoint on the fruit morphogenesis is proposed and justified, comprising the pre-anthetic, as well as post-anthetic periods of fruit development, id est, development of the gynoecium, and development of the fruit itself. It is proposed to recognize ontogenetical (individual) and evolutionary (historical) aspects of fruit morphogenesis, the first of them we can study directly, while the second aspect can be only hypothesized or treated as a theoretical model of fruit evolution in consequence of some presumed changes in the individual fruit morphogenesis. In this article these aspects are named as "ontomorphogenesis" and "phylomorphogenesis" of the fruit, correspondingly. Our concept of ontomorphogenesis of the fruit involves four components that could not be brought together, such as changes in the morphological structure of the gynoecium, abscission of the extragynecial floral parts and the style, histogenesis of the fruit wall and other fruit parts, and terminal stages of the fruit morphogenesis (dehiscence, splitting, or abscission). The current state of studies of these components in the individual and evolutionary contexts is discussed. By examining the patterns of fruit evolution, we should consider factors acting at both the post-anthetic and pre-anthetic periods of fruit ontomorphogenesis.

Yerel Zeytin Çeşitlerindeki Pomolojik Değişimlerin Farklı Hasat Zamanlarında Belirlenmesi

Olive (Olea europaea L.) is an important oil producing fruit species and it has been cultivated since ancient times. Turkey is rich in local olive varieties and it is necessary to determine their pomological parameters. The aim of the present study was to determine the pomological characteristics of five olive varieties (Çekişte, Memecik, Yamalak sarısı, Eşek zeytini, Gemlik) at five harvest periods (H1-H5) throughout the fruit development period. Olives were collected from an orchard in Aydın at monthly intervals between July and November 2019. During fruit development and ripening, 10 pomological variables (fruit width and length, seed width and length, fruit and seed weight, flesh weight, flesh/seed ratio, flesh firmness and fruit moisture content) were measured. All pomological variables exhibited significant differences between harvest periods and varieties. While fruit ripening indices of the varieties increased over time, level of change differed among the varieties. During fruit ripening of olive varieties, fruit length and width, fruit weight, seed length and width, fruit flesh weight and flesh/seed ratio increased significantly, while flesh firmness and fruit water contents decreased. Seed weight increased between H1-H3 periods, but it did not show a significant change at the later stages of fruit development. These results show that important physiological changes occur starting from the pit hardening of the olive varieties and continue throughout the fruit growth and ripening.

The Effects of Bagging on Color Change and Chemical Composition in ‘Jinyan’ Kiwifruit (Actinidia chinensis)

To explore the effect of bagging on the nutritional quality and color of kiwifruit (Actinidia spp.), the fruits of yellow-fleshed kiwifruit cultivars were analyzed after bagging treatment. Bagging treatment promoted the degreening of mesocarp and increased brightness. Bagging significantly reduced the accumulation of dry matter, titratable acids, starch, sucrose, fructose, and glucose during kiwifruit development. Additionally, bagging significantly reduced the accumulation of chlorophyll and carotenoids during development, whereas after debagging, the chlorophyll and carotenoid contents were significantly increased. Gene expression analysis showed that during most of the fruit development periods, the chlorophyll biosynthesis genes AcRCBS, AcGLUTR, and AcCHLG, and degradation genes AcCBR, AcPAO, AcPPH, AcCLH, and AcSGR had significantly lower expression levels in bagged fruit. Bagging also inhibited the expression of carotenoid metabolism genes, especially AcSGR and AcLCYB, which may play a key role in the process of fruit development during bagging by decreasing the accumulation of chlorophyll and carotenoids in kiwifruit. Additionally, bagging significantly reduced the content of AsA. The expression of the AsA biosynthesis genes AcPMI2, AcGPP2, and AcGalDH in bagged fruit was significantly lower than in the control, indicating that these may be the key genes responsible for the difference in the accumulation of AsA after bagging.

English

Carotenoids are important substances for the yellow color of peach flesh. In this study, the contents of carotenoids in two yellow flesh peach varieties ('Zhongtao Jinmi' and 'Jinxiang') and one white flesh peach variety ('Bairuyu') were determined by high-performance liquid chromatography. The results showed that the carotenoid content in the two yellow flesh peach varieties increased with fruit development and reached the maximum of 25.80 and 27.63 μg.g-1 at the mature stage, while that of the white flesh peach variety remained at a very low level during the whole fruit development period. Furthermore, transcriptome sequencing was performed to analyze the differentially expressed genes (DEGs) during fruit development among the three peach varieties. Among these DEGs, four candidate genes were identified to be potentially involved in the biosynthesis of carotenoids, including LOC18774744 (encoding UDP-glycosyltransferase 87A1 (UGT87A1)), LOC18792568 (encoding the carotenoid cleavage dioxygenase 4 gene (CCD4)), LOC109949966 (an unannotated gene), and LOC18779468 (encoding xyloglucan endoglucosylase/hydrolase protein 8. qRT-PCR confirmed that the expression of LOC109949966 and LOC18779468 in two yellow flesh varieties was significantly higher than that in the white flesh variety, while it was the opposite case for UGT87A1 and CCD4. Therefore, we speculate that CCD4 is directly involved in regulating carotenoid synthesis, while other three genes may play some indirect roles in the process. Our findings are expected to improve the understanding on the mechanism of carotenoid biosynthesis in peach. © 2022 Friends Science Publishers

Management of Litchi Fruit and Shoot Borer (Conomorpha sinensis) in Three Litchi Varieties in Samtenling, Bhutan

In Bhutan, litchi production is constrained by insect pest damage. Among insect pests, the litchi fruit and shoot borer (Conopomorpha sinensis Bradley) is an emerging pest of economic importance in the subtropical regions of Bhutan. Up until now, there is documented research on its biology and management in Bhutan. Therefore, this study was undertaken to study the efficacy of two different management methods against litchi fruit borer infestation in three litchi varieties (Bhur litchi 1, Bhur litchi 2 & Hong houy). The management methods consisted of three treatments; T1-Azadirachtin followed by Imidacloprid, Azadirachtin and Cypermethrin; T2-Azadirachtin followed by Imidacloprid, Azadirachtin and Azadirachtin; T3-Untreated control. The result showed that the fruit infestation at harvest was significantly lower in management method T1 (34.74%) as compared to T2 (78.07%) and untreated control (89.98%). In terms of the variety, the lowest fruit infestation at harvest was observed for Hong houy (56.02%) as compared to Bhur Litchi 1 (73.28%) and Bhur Litchi 2 (73.45%). There were no significant differences in fruit drop percent and percent infestation of dropped fruits between the treatments and varieties tested. Heavy fruit drop was observed in the third week, due to unknown reasons, which then decreased over the fruit development stages. Fruit borer infestation seems to increase rapidly after the fifth and eighth weeks indicating that most of the fruit borer damage occurs at the fruit maturity stage after fruit colour break. Therefore, the last application of cypermethrin 10% EC at the fruit colour break stage was found necessary to reduce fruit infestation during this vulnerable pest infestation period besides scheduled application of Azadirachtin and Imidacloprid at the early fruit development period.

Sugar, Invertase Enzyme Activities and Invertase Gene Expression in Different Developmental Stages of Strawberry Fruits.

The cultivated strawberry (Fragaria × ananassa) is octoploid (2n = 8x = 56) and has been the focused fruit species of which an increasing number of molecular and genetic research has been conducted in recent years. The aim of this study is to identify the relationships between sucrose metabolism, invertase enzyme activity and gene expression in four different fruit development periods (red, pink, green and white) of two commercially important strawberry varieties ‘Rubygem’ and ‘Fortuna’. The metabolite profiles (glucose, fructose, sucrose and total sugar content) of two varieties were discovered to be extremely similar. The highest amount of total sugar was found in red fruits, while the lowest was obtained from green fruits. Invertase represents one of the key enzymes in sucrose metabolism. The lowest invertase activity was obtained from the green fruits in ‘Rubygem’ and ‘Fortuna’ during four developmental periods. In these varieties, the amount of sucrose was found to be close to glucose and fructose and the lowest amount was detected in green period, while invertase activity was relatively high during red and pink periods and invertase gene expression was determined at high levels in both primers (St-4 and St-6) in the green period. The results of the study indicated that sugar content and invertase activity were positively correlated while enzyme activity and gene expression were negatively correlated.

Sustainable Silage Maize Integrated Protection against the European Corn Borer Ostrinia nubilalis and the Corn Earworm Helicoverpa armigera Employing the Farm Irrigation System

Silage corn is an important source of feed in animal husbandry, often affected by the feeding action of diverse corn borers that can compromise harvest quality and quantity. According to the need to reduce the use of chemical insecticides, the main purpose of this study was to evaluate the efficacy of different IPM programs comparing microbial (Btk and baculovirus) and chemical control methods, alone or combined, against O. nubilalis and H. armigera. Assessments were based on counting the number of larvae, inspecting plants superficially and inside the stem, and estimating the derived damages. All tested products proved to be effective in containing the density of these lepidopteran species, with microbial control agents having comparable efficacy in respect to the reference chemical substances (lambda-cialotrina and chlorantraniliprole), even if periodic treatment repetition was required to ensure over-time protection until harvest. Both Btk and HaNPV were successfully applied by the irrigation system during flowering and fruit development periods, when plant height did not allow the use of a tractor-mounted spray bar. This biocontainment approach appears to be sustainable and technically compatible with farm needs.

Phenotyping in flower and main fruit traits of Chinese cherry [Cerasus pseudocerasus (Lindl.) G.Don

Chinese cherry [Cerasus pseudocerasus (Lindl.) G.Don], native to China, is an economically important tetraploid fruiting cherry species. In order to perfect the cherry germplasm descriptors system, and effectively rate on characters in DUS (distinctness, uniformity, stability) testing, we comprehensively investigated and analyzed 38 Chinese cherry phenotypes, including phenological records, flower, pit and main fruit quality traits, of 59 germplasm collections and 950 individuals from four cross F1 populations. An index system for Chinese cherry DUS test was firstly established by statistically phenotyping 26 traits. The results showed that the fruit development period ranged from 43 to 69 days, which could be well applied to evaluate the maturity time and were divided into five ratings. Thirteen qualitative characters, including two in flower, five in fruit, and six in pit, were classified into two to six ratings, respectively. Significant variations were detected among these characters, with Shannon-Wiener indexes ranging from 0.37 to 1.49. The average coefficient of variation was 20.94% ranging from 5.48 to 76.56% among 22 quantitative traits. The fruit weight, size, firmness, pit weight, titratable acid and soluble solid mainly contributed to the phenotypic variations by principal component analysis. Eight fruit and pit characters, which were in accordance with the normal distribution, were rating by the least significant difference method, while four fruit characters, being out of the normal distribution, were rating by the range method. The establishment of phenotyping protocol will enrich cherry descriptors system and DUS test guideline, and provide important basis for marker-assisted breeding in Chinese cherry.

Genome-Wide Identification of Loci Associated With Phenology-Related Traits and Their Adaptive Variations in a Highbush Blueberry Collection.

Genetic variation in phenological traits is the key in expanding production areas of crops. Southern highbush blueberry (SHB) is a blueberry cultivar group adapted to warmer climates and has been developed by multiple interspecific hybridizations between elite northern highbush blueberry (NHB) (Vaccinium corymbosum L.) and low-chill Vaccinium species native to the southern United States. In this study, we employed a collection of diverse SHB accessions and performed a genome-wide association study (GWAS) for five phenology-related traits [chilling requirement (CR), flowering date, ripening date, fruit development period, and continuous flowering] using polyploid GWAS models. Phenology-related traits showed higher heritability and larger correlation coefficients between year replications, which resulted in the detection of robust phenotype–genotype association peaks. Notably, a single association peak for the CR was detected on Chromosome 4. Comparison of genotypes at the GWAS peaks between NHB and SHB revealed the putative introgression of low-chill and late-flowering alleles into the highbush genetic pool. Our results provide basic insights into the diversity of phenological traits in blueberry and the genetic establishment of current highbush cultivar groups.

Difference Between Coloration and Endogenous Abscisic Acid Accumulation Patterns in Two Red Grape Cultivars, ‘Aki Queen’ and ‘Ruby Roman’ (<i>Vitis labruscana</i> Bailey) Berries

Changes in anthocyanin and endogenous abscisic acid (ABA) contents in the berry skins of Vitis labruscana × V. vinifera cultivars, ‘Aki Queen’, and ‘Ruby Roman’ were investigated during the fruit development period. Color development of ‘Aki Queen’ berries mainly occurred within 20 days post véraison, while that of the ‘Ruby Roman’ was prolonged for about 40 days. In both cultivars, the ABA level in the berry skin started to increase a few days before véraison; however, ABA accumulation ceased approximately 10 days after véraison in ‘Aki Queen’, while it continued until the late stage of maturation in ‘Ruby Roman’. In addition, higher indole-3-acetate aspartate (IAA-Asp) and lower isopentenyladenine (iP) contents were observed in ‘Ruby Roman’ than in ‘Aki Queen’ at the late development stage. The expression analysis of genes involved in ABA metabolism revealed that V. vinifera 9-cis-epoxycarotenoid dioxygenase 3 (VviNCED3), which is assumed to play a major role in ABA biosynthesis, remained relatively higher in ‘Ruby Roman’ than in ‘Aki Queen’ after véraison. Considering that ABA plays a regulatory role in grape maturation, these results may indicate that the coloration of ‘Ruby Roman’ at the later stage of maturation is partly attributable to an increased ABA pool in berry skins.

Potassium dynamics in orchard soil and potassium status of sour cherry trees affected by soil nutritional conditions

The influence of mineral fertilizers on the seasonal dynamics of exchangeable potassium in the soil, potash status and productivity of trees was studied in field experiment with sour cherry trees cv. ‘Turgenevka’ in soil-climatic condition of Central Russian upland in 2018-2019. The urea and potassium sulfate were applied annually in early spring at doses of N30K40, N60K80, N90K120, and N120K160 kg/ha. The potassium level in soil-plant system depended on weather conditions, the doses of fertilizers and uptake of the element by trees. The reserves of exchangeable potassium in loamy Haplic Luvisol at the level of 100-200 mg/kg were sufficient to ensure the sour cherry yield in the start of fruiting. Fertilization by doses of N60K80 and higher increased the content of exchangeable potassium in root zone (more than 200 mg/kg), but the features of potassium seasonal dynamics were similar to unfertilized plots. With increase in the average fruit load from 4.6 (2018) to 8.3 (2019) kg/tree, the uptake of potassium by young trees increased, which led to a significant decrease in the concentration of potassium in the soil and leaves during the fruit development period (June and July). Fertilization reduced this effect but did not significantly influence on the productivity of trees and fruit potassium status.

Flower and fruit development of a low-chill peach, ‘KU-PP2’ in plastic houses with and without heating

Although ‘KU-PP2’, a low-chill peach cultivar, was released for high-quality peach production under forcing culture, the performance of ‘KU-PP2’ trees under forcing conditions has yet to be determined. In this study, we investigated the spring phenology, fruit development, and fruit quality of ‘KU-PP2’ in a heated plastic house compared with the same traits in an unheated plastic house and open field conditions. We found that the forcing conditions accelerated the spring phenology and harvest period of ‘KU-PP2’. Heated conditions shortened the number of days from dormancy release to blooming and the length of the fruit development period, resulting in the blooming of flowers in late February, with fruit begin harvested as early as mid-May, which was notably earlier than blooming and fruit harvest under natural conditions by 4 and 6 weeks, respectively. Similarly, the unheated conditions accelerated the time to blooming and harvest by up to 3 and 4 weeks, respectively compared with the open field conditions. However, although the fruit produced by trees raised in the heated plastic house could be harvested at an earlier date, the amount of fuel used for the heating system was 50 L per tree, which could be prohibitively expensive for commercial production. Although the fruit growth pattern did not differ significantly between the forcing and natural conditions, the rate of fruit growth at stages S1 and S2 was higher in the heated plastic house than that under the other assessed conditions. Furthermore, the size and quality of fruit obtained under forcing conditions were slightly larger and superior, respectively, than those of fruit produced under natural conditions. Moreover, we found no evidence of split-pits under the forcing conditions. The findings of this study accordingly indicate that cultivation of the low-chill peach ‘KU-PP2’ under forcing conditions is conducive to a notably earlier harvest of fresh peaches. These observations advance our current understanding of the flowering, fruit development, and fruit production of low-chill peaches under forcing conditions.

Existence of Vivipary in Mango (Mangifera indica cv. ‘Amrapali’) – A Report

Aim: The Amrapalii cultivar of mango is known for its dwarf stature, high productivity and ability to capture the market late when mango from other regions of the country gets over. Vivipary is of unusual occurrence in mango. The aim of the study is to report the occurrence of vivipary in mango especially in cultivar Amrapali under the sub-Himalayan subtropics of India.
 Materials and Methods: Incidental occurrence of vivipary in mango has been reported from the Hamirpur district of Himachal Pradesh during the growing season of the year 2021. Upon observance of abnormal protuberances from the fruit surface, the harvesting was commenced at the weekly intervals and the per cent proportion of viviparous fruits was ascertained by cutting the fruits longitudinally and confirming the viviparous germination of the seeds. Weather data of the fruit development state were analysed for the accumulation of heat units and rainfall distribution. Efforts have been made for ascertaining the reason behind the viviparous seed development.
 Results and Discussion: The proportion of viviparous seeds increased with the progression of time and by the mid of September, more than 12% of seeds were found viviparous. The weather data show that there was an early accumulation of heat units. Also, the rainfall during the period of fruit development was high particularly at the time when fruits were advancing toward maturity.
 It has been observed that the seed maturity has preceded the fruit pulp maturity and ripening may be due to the early accumulation of heat units and high rainfall. This coincidence might have resulted in precocious germination of seed inside the fruit, leading to vivipary.
 Conclusion: The development of vivipary in Amrapali mango has been found to be associated with the early accumulation of heat units and high rainfall. Under the current changing climatic scenario, a need has been projected for strategic research for curtailing vivipary incidences and saving economic losses to the growers of late mango varieties in the sub-Himalayan subtropics.

Survey of Florida Olive Groves during Olive Fruit Development: Monitoring for Stink Bugs and Olive Fruit Flies

Olives, Olea europaea L. (Oleaceae), are an emerging commercial crop in Florida; however, potential arthropod threats during olive tree establishment and fruit development remain uncharacterized. Two potential pests that may threaten olive fruit production directly are native and invasive pentatomid stink bugs, which are important pest species of many crops in the southeast, and the invasive olive fruit fly, Bactrocera oleae (Gmelin) (Diptera: Tephritidae),which is not known to be established in Florida. Monitoring for stink bugs during fruit maturation was done using dual funnel tube traps baited with stink bug lures. Yellow sticky card traps baited with food and pheromone lures were used to monitor for the olive fruit fly. Both trap types were placed in tree canopies in 4 North Central Florida olive groves during the anticipated fruit development period for 2 growing seasons. Whereas neither of the invasive species targeted (Halyomorpha halys Stål [Hemiptera: Pentatomidae] or B. oleae) were detected, several other potential pests were identified including brown stink bugs (Euschistus spp.; Hemiptera: Pentatomidae), glassy winged sharpshooters, Homalodisca vitripennis Germar (Hemiptera: Cicadellidae), and grasshoppers. No fruit damage attributable to arthropod pests was detected although fruit production was very low with limited samples. These results contribute to awareness of potential pests that may jeopardize olive fruit production and aid in the future studies to develop effective monitoring activities for Florida growers.

Heterologous expression of the peach sucrose transporter (PpSUT2) in increased cold and drought stress tolerance in tobacco

ABSTRACT Peach is an important fruit tree worldwide. Sucrose transporters (SUTs) have been extensively studied in relation to plant growth, development, and stress responses. In this study, we cloned a putative SUT, PpSUT2, from the peach cultivar ‘New Kawanakajima.’ Bioinformatics analysis predicted that the protein had functional domains typical of the GPH_sucrose family. Phylogenetic analysis revealed high sequence similarity between PpSUT2 and SUTs from other plant species. The qRT-PCR suggested that PpSUT2 was expressed concurrently in the petals, sepals, pistils, stamen, phloem, and leaves. Different trends and different relative expression levels were observed during the flowering and fruit development periods. Western blot analysis produced similar results. The heterologous expression of SUTs in the defective yeast SUSY7/ura3 showed that PpSUT2 had a complementary function on SD sucrose medium. This indicated that it had sucrose transport activity and might be a signal protein. Then, 11PpSUT2 transgenic tobacco plants were obtained.After exposure to low temperature and drought stress conditions, the transgenic overexpression plants exhibited increased proline and soluble sugar content, reduced malondialdehyde (MDA) content and reduced relative conductivity, and less membrane injury. These results suggest that the overexpression of PpSUT2 in tobacco promoted greater resistance to cold and drought.

Microclimate suitability for green and coloured sweet pepper hybrids in open and protected structures in sub-tropical humid climate of West Bengal

A study was undertaken for two consecutive seasons (autumn-winter) to evaluate the performance of three green, red and yellow-fruited sweet pepper hybrids in open field and under two protected structures (50% green shade net house and naturally-ventilated polyhouse) to understand the microclimate suitability for maximizing the productivity of these hybrids under sub-tropical humid climatic condition of eastern India. In this climatic condition, naturally-ventilated polyhouse was most suitable for enhancing fruit yieldof both green and coloured fruited hybrids. Open field condition was not suitable for both yellow and redfruited hybrids. Though green-fruited hybrids could be grown in open field condition, fruit yield was more than double under polyhouse. Shade net house could not be considered as a suitable protected structure for sweet pepper in this climatic condition because of reduced light intensity and high relative humidity inside it causing low fruit set and high incidence of bacterial wilt disease. Maximum/minimum temperature30oC to 33oC / 14oC to 17oC with comparatively reduced light intensity of 35,000 to 55,000 lux, prevention of adverse effect of low night temperature during winter and  60 per cent relative humidity condition during flowering, fruit set and fruit development period inside the naturally ventilated polyhouse were most suitable growing conditions for getting maximum productivity of both green and colour-fruited hybrids of sweet pepper.