Bioinformatic and expression analysis of the OMT gene family in Pyrus bretschneideri cv. Dangshan Su.

With high nutritional value in its fruits, Dangshan Su pear has been widely cultivated in China. The stone cell content in fruits is a key factor affecting fruit quality in pear, and the formation of stone cells has been associated with lignin biosynthesis. O-Methyltransferase (OMT) is a key enzyme involved in lignin metabolism within the phenylpropanoid pathway. Here, we screened 26 OMT genes from the Pyrus bretschneideri cv. Dangshan Su genome using the DNATOOLs software. To characterize the OMT gene family in pear, gene structure, chromosomal localization, and conserved motifs of PbOMTs were analyzed. PbOMTs were divided into two categories, type I (designated PbCCOMTs) and type II (designated PbCOMTs), indicating the differentiation of function during evolution. Based on the analysis of multiple sequence alignment, cis-element prediction, and phylogenetic relationships, two candidate genes, PbCCOMT1 and PbCCOMT3, were selected for the analysis of temporal and spatial gene expression in pear. The promoter regions of both PbCCOMT1 and PbCCOMT3 contain regulatory motifs for lignin synthesis. Moreover, the two genes show high similarity and close phylogenetic relationships with CCOMTs in other species. Expression analysis showed that transcript levels of two PbCCOMTs were positively associated with the contents of both stone cells and lignin during the development of pear fruit. These results suggest that PbCCOMT1 and PbCCOMT3 are closely associated with lignin biosynthesis. These findings will help clarify the function of PbOMTs in lignin metabolism and to elucidate the mechanisms underlying stone cell formation in pear.

Influence of rootstocks on growth, yield, fruit quality and leaf mineral element contents of pear cv. 'Santa Maria' in semi-arid conditions.

BACKGROUND: Rootstocks play an essential role to determining orchard performance of fruit trees. Pyrus communis and Cydonia oblonga are widely used rootstocks for European pear cultivars. The lack of rootstocks adapted to different soil conditions and different grafted cultivars is widely acknowledged in pear culture. Cydonia rootstocks (clonal) and Pyrus rootstocks (seedling or clonal) have their advantages and disadvantages. In each case, site-specific environmental characteristics, specific cultivar response and production objectives must be considered before choosing the best rootstock. In this study, the influence of three Quince (BA 29, Quince A = MA, Quince C = MC) and a local European pear seedling rootstocks on the scion yield, some fruit quality characteristics and leaf macro (N, P, K, Ca and Mg) and micro element (Fe, Zn, Cu, Mn and B) content of 'Santa Maria' pear (Pyrus communis L.) were investigated. RESULTS: Trees on seedling rootstock had the highest annual yield, highest cumulative yield (kg tree(-1)), largest trunk cross-sectional area (TCSA), lowest yield efficiency and lowest cumulative yield (ton ha(-1)) in the 10(th) year after planting. The rootstocks had no significant effect on average fruit weight and fruit volume. Significantly higher fruit firmness was obtained on BA 29 and Quince A. The effect of rootstocks on the mineral element accumulation (N, K, Ca, Mg, Fe, Zn, Cu, Mn and B) was significant. Leaf analysis showed that rootstocks used had different mineral uptake efficiencies throughout the early season. CONCLUSION: The results showed that the rootstocks strongly affected fruit yield, fruit quality and leaf mineral element uptake of 'Santa Maria' pear cultivar. Pear seedling and BA 29 rootstock found to be more prominent in terms of several characteristics for 'Santa Maria' pear cultivar that is grown in highly calcareous soil in semi-arid climate conditions. We determined the highest N, P (although insignificant), K, Ca, Mg, Fe and Cu mineral element concentrations on the pear seedling and BA 29 rootstocks. According to the results, we recommend the seedling rootstock for normal density plantings (400 trees ha(-1)) and BA 29 rootstock for high-density plantings (800 trees ha(-1)) for 'Santa Maria' pear cultivar in semi-arid conditions.

Influence of rootstocks on growth, yield, fruit quality and leaf mineral element contents of pear cv. 'Santa Maria' in semi-arid conditions

BACKGROUND: Rootstocks play an essential role to determining orchard performance of fruit trees. Pyrus communisand Cydonia oblonga are widely used rootstocks for European pear cultivars. The lack of rootstocks adapted to different soil conditions and different grafted cultivars is widely acknowledged in pear culture. Cydonia rootstocks (clonal) and Pyrus rootstocks (seedling or clonal) have their advantages and disadvantages. In each case, site-specific environmental characteristics, specific cultivar response and production objectives must be considered before choosing the best rootstock. In this study, the influence of three Quince (BA 29, Quince A = MA, Quince C = MC) and a local European pear seedling rootstocks on the scion yield, some fruit quality characteristics and leaf macro (N, P, K, Ca and Mg) and micro element (Fe, Zn, Cu, Mn and B) content of 'Santa Maria' pear (Pyrus communis L.) were investigated. RESULTS: Trees on seedling rootstock had the highest annual yield, highest cumulative yield (kg tree(-1)), largest trunk cross-sectional area (TCSA), lowest yield efficiency and lowest cumulative yield (ton ha(-1)) in the 10th year after planting. The rootstocks had no significant effect on average fruit weight and fruit volume. Significantly higher fruit firmness was obtained on BA 29 and Quince A. The effect of rootstocks on the mineral element accumulation (N, K, Ca, Mg, Fe, Zn, Cu, Mn and B) was significant. Leaf analysis showed that rootstocks used had different mineral uptake efficiencies throughout the early season. CONCLUSION: The results showed that the rootstocks strongly affected fruit yield, fruit quality and leaf mineral element uptake of 'Santa Maria' pear cultivar. Pear seedling and BA 29 rootstock found to be more prominent in terms of several characteristics for 'Santa Maria' pear cultivar that is grown in highly calcareous soil in semi-arid climate conditions. We determined the highest N, P (although insignificant), K, Ca, Mg, Fe and Cu mineral element concentrations on the pear seedling and BA 29 rootstocks. According to the results, we recommend the seedling rootstock for normal density plantings (400 trees ha(-1)) and BA 29 rootstock for high-density plantings (800 trees ha(-1)) for 'Santa Maria' pear cultivar in semi-arid conditions.

Characterization of Anatolian traditional quince cultivars, based on microsatellite markers.

We conducted simple sequence repeat (SSR) analyses of 15 traditional quince (Cydonia oblonga) cultivars from Anatolian gene sources for molecular characterization and investigation of genetic relationships. Three pear and two apple cultivars were used as references for SSR locus data analysis and to determine allele profiles between species. Eight SSR loci that were developed from apple and pear were used, and a total of 44 alleles were found among quince cultivars. The CH01F02 locus was found to have the highest identification probability, while the CH04E03 locus had the lowest identification probability. Analysis of similarity ratios between quince cultivars showed that the lowest similarity ratio was 18% (Esme-Bardacik ± k), while the highest similarity ratio was 87% (Bursa-Osmancik ± k and Osmancik ± k-Viranyadevi). In the phylogenetic dendrogram, Esme quince showed separate branching from other quince cultivars, and no synonymous accessions were found. These results suggest that SSR markers from pear and apple could be used to determine genetic variation among quince cultivars. These findings can be used to guide future quince breeding and management studies.

Peras‘Packhams Triumph processadas em diferentes tipos de corte e armazenadas em diferentes temperaturas / ‘Packhams Triumph pears processed in different types of cutting and stored at different temperatures

O tempo de deterioração de frutas minimamente processadas é diretamente proporcional à sua taxa respiratória, sendo a temperatura de armazenamento um dos fatores que mais infl uenciam na vida de prateleira destes produtos. Os danos causados pelo corte aumentam a taxa respiratória e reações bioquímicas, tal como o escurecimento enzimático. O objetivo deste trabalho foi avaliar o efeito de três tipos de cortes (em fatias, cubos e metades) e duas temperaturas de armazenamento (5°C e 8°C) na taxa respiratória e na coloração de polpa de peras ‘Packhams Triumph minimamente processadas e acondicionadas em embalagem rígidas de polietileno com tampa durante sete dias de armazenagem. Logo após o processamento, a taxa respiratória das frutas submetidas ao corte em fatias e armazenadas a 8°C, e ao corte em cubos e armazenadas a 5°C e 8°C apresentou-se 62% maior que peras submetidas ao corte em fatias e mantidas a 5°C. Aos sete dias de armazenamento, a taxa respiratória foi menor a 5°C, sem diferenças quanto ao tipo de corte. O tipo de corte afetou o atributo L (escurecimento) da polpa, com as metades e cubos não apresentando escurecimento (L=75,4-75,9), como as fatias (L=72,8). Os valores de a*, Hab e C* indicam que houve maior escurecimento das fatias armazenadas a 8°C.(AU)

The deterioration rate of minimally processed fruit is proportional to its respiratory rate, and the storage temperature is one of the factors that most infl uence it. Damages caused by cutting increase respiration and biochemical reactions such as browning. The objective of this study was to evaluate the effect of three types of cuts (sliced, diced and in halves) and two storage temperatures (5°C and 8°C) on the respiratory rate and color attributes of ‘Triumph Packhams pears stored in closed rigid polyethylene containers for seven days. After processing, the respiratory rate of pears slices stored at 8°C and pear cubes stored at 5 and 8°C was 62% higher than the pear cut into slices and stored at 5°C. On day seven, the respiratory rate was lower at 5°C and did not show any differences according to the type of cut. The type of cut affected the color parameter L (lightness). The fruit cut in alves and cubes did not show any browning (L = 75.4 to 75.9), as opposed to the sliced fruit (L = 72.8). The values of a*, C* and Hab indicated that slices stored at 8°C showed the highest browning rate.(AU)

Peras‘Packham’s Triumph’ processadas em diferentes tipos de corte e armazenadas em diferentes temperaturas / ‘Packham’s Triumph’ pears processed in different types of cutting and stored at different temperatures

O tempo de deterioração de frutas minimamente processadas é diretamente proporcional à sua taxa respiratória, sendo a temperatura de armazenamento um dos fatores que mais infl uenciam na vida de prateleira destes produtos. Os danos causados pelo corte aumentam a taxa respiratória e reações bioquímicas, tal como o escurecimento enzimático. O objetivo deste trabalho foi avaliar o efeito de três tipos de cortes (em fatias, cubos e metades) e duas temperaturas de armazenamento (5°C e 8°C) na taxa respiratória e na coloração de polpa de peras ‘Packhams Triumph’ minimamente processadas e acondicionadas em embalagem rígidas de polietileno com tampa durante sete dias de armazenagem. Logo após o processamento, a taxa respiratória das frutas submetidas ao corte em fatias e armazenadas a 8°C, e ao corte em cubos e armazenadas a 5°C e 8°C apresentou-se 62% maior que peras submetidas ao corte em fatias e mantidas a 5°C. Aos sete dias de armazenamento, a taxa respiratória foi menor a 5°C, sem diferenças quanto ao tipo de corte. O tipo de corte afetou o atributo L (escurecimento) da polpa, com as metades e cubos não apresentando escurecimento (L=75,4-75,9), como as fatias (L=72,8). Os valores de a*, Hab e C* indicam que houve maior escurecimento das fatias armazenadas a 8°C.

The deterioration rate of minimally processed fruit is proportional to its respiratory rate, and the storage temperature is one of the factors that most infl uence it. Damages caused by cutting increase respiration and biochemical reactions such as browning. The objective of this study was to evaluate the effect of three types of cuts (sliced, diced and in halves) and two storage temperatures (5°C and 8°C) on the respiratory rate and color attributes of ‘Triumph Packhams’ pears stored in closed rigid polyethylene containers for seven days. After processing, the respiratory rate of pears slices stored at 8°C and pear cubes stored at 5 and 8°C was 62% higher than the pear cut into slices and stored at 5°C. On day seven, the respiratory rate was lower at 5°C and did not show any differences according to the type of cut. The type of cut affected the color parameter L (lightness). The fruit cut in alves and cubes did not show any browning (L = 75.4 to 75.9), as opposed to the sliced fruit (L = 72.8). The values of a*, C* and Hab indicated that slices stored at 8°C showed the highest browning rate.