scholarly journals DNA-based determination of suitable pollinating cultivars for the pear cultivar 'Carola' (Pyrus communis)

Author(s):  
H. Nybom ◽  
J. Sehic ◽  
H. Mattisson

Pollen-limited fruit set has long been suspected in some relatively low-yielding orchards with the Swedish pear cultivar 'Carola'. Fruit was therefore harvested on 23 'Carola' trees in a commercial pear orchard. The seeds were germinated and five seedlings from each tree were sampled to determine which of the surrounding cultivars had been the most successful pollinators. Leaves of 'Carola', the 7 putative pollinating cultivars and the 115 seedlings were analysed with 6 RAPD primers. By comparison of the band patterns, paternity could be ascertained for 74 seedlings. The by far most successful pollinator was 'Clara Frijs' which had sired approx. half of the seedlings, followed by 'Herzogin Elsa', `Skanskt Sockerpiiron', 'Alexandre Lucas', 'Coloree de Juillet' and 'Doyenne du Cornice'. The latter is the maternal parent of 'Carola', and these two cultivars must therefore share one S-allele and hence can only be semi-compatible. In addition, 6% of the seedlings were in all likelihood derived from selling_ since they showed no bands that did not occur also in 'Carola'. Maximum distance between 'Carola' trees and suitable pollinators should not exceed 15-20 tn. Longer distances may produce a serious dearth of compatible pol­len as evidenced by the large percentage of seedlings derived either from selling. (25%) or from long-distance (> 40 m) pollen transfer (25%) when 'Carola' trees were surrounded by non-preferred pollinators.

Author(s):  
H. Mattison ◽  
J. Sehic ◽  
H. Nybom

In commercial fruit tree orchards, consistently high yields are necessary for a durable economy. The Swedish pear cultivar 'Carola' has been noted for low setting in some orchards, possibly due to insufficient pollination. In this study, fruit set was evaluated in a research orchard where `Carola' had been planted together with four potential pollinators. Total yield and number of fruits was noted during three and four years, respectively. In 2003, seeds were germinated from the harvested `Carola' fruits, and the paternity of three seedlings from 50 trees was determined with RAPD analysis. 'Clapp's Favourite' had sired 39.6% of the seedlings, closely followed by `Seigneur d'Esperen' (30.7%) and 'Clara Frijs' (26.7%) whereas 'Skanskt sockerparon' only sired 1.1% of the seedlings. The remaining 2.3% appeared to have been derived by selfing. Pollen-limited seed set was indicated at surprisingly short distances; accumulated number of fruits on the `Carola' trees was significantly higher when separated by only 2 m from one of the two most efficient pollinators, 'Clapp's Favourite' or 'Seigneur d'Esperen‘, compared to trees 4—l0 in away in the same row. Number of viable seeds per fruit was also higher in fruits from trees immediately adjacent to the pollinators, suggesting an effect of improved pollination success. The importance of very short inter-cultivar distances for efficient pollen transfer became even more clear when comparisons involved the true pollination distances as determined by RAPD; the accumulated yields decreased linearly from 55 kg at a 2 in distance to only 17 kg at 13 m.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1175
Author(s):  
Jiovan Campbell ◽  
Pranavkumar Gajjar ◽  
Ahmed Ismail ◽  
Fariborz Habibi ◽  
Ahmed G. Darwish ◽  
...  

In this study, fertility-related traits of 90 muscadine grape genotypes were evaluated. Selected genotypes included 21 standard cultivars, 60 breeding lines, and nine Vitis × Muscadinia hybrids (VM hybrids). The first fruiting bud (FFB), bud fertility (BF), bud fertility coefficient (BFC), number of flowers/flower cluster (N.F/FC), fruit-set efficiency (FSE), number of clusters/vine (N.C/V), and yield/vine (Y/V) traits were evaluated. The FFB trait did not show significant differences among genotypes. The muscadine genotype O28-4-2-2 (1.6 ± 0.2) displayed the FFB closest to the base; however, O17-16-2-1, O18-2-1, and VM A12-10-2 genotypes had the most distant FFB (3.6 ± 0.3). All the other fertility-related traits varied widely among the population. The BF, BFC, N.F/FC, FSE, N.C/V, and Y/V exhibited a range estimated at 35.1%, 81.5%, 259.7, 63.3%, 177 C/V, and 22.3 kg/V, respectively. The muscadine genotypes O42-3-1 (36.7% ± 1.3) and Majesty (34% ± 1.2) exhibited the highest BF; however, the VM A12-10-2 (1.6% ± 0.1) recorded the lowest BF. The VM genotype O15-16-1 (82.8% ± 4.1) displayed the highest BFC; however, the VM A12-10-2 (1.3% ± 0.1) showed the lowest BFC. The muscadine genotypes D7-1-1 (280.3 F/FC ± 21.7) and O17-17-1 (20.7 F/FC ± 5.5) showed the highest and lowest N.F/FC, respectively. The maximum and minimum FSE was observed for the Rosa cultivar (65.7% ± 2.4) and muscadine genotype D7-1-1 (2.4% ± 0.2), respectively. The minimum N.C/V was recorded for VM genotype A12-10-2 (6 C/V ± 0.2) and maximum noted for muscadine genotypes B20-18-2 (183 C/V ± 7.5) and O44-14-1 (176 C/V ± 7.3). Muscadine genotype O23-11-2 (22.6 kg ± 1.1) produced the highest Y/V; however, the lowest yield was recorded for O15-17-1, Fry Seedless, Sugargate, and the VM genotypes and A12-10-2, with an average yield among them estimated at 0.4 kg ± 0.2.


Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1814
Author(s):  
Agnieszka Stasiak ◽  
Piotr Latocha ◽  
Monika Bieniasz

Successful pollination and fertilization are crucial processes for obtaining a high yield, especially for dioecious plants such as A. arguta. Determination of pollen tube growth on stigma and fruit development parameters, which were investigated in this study, can enable the evaluation of male–female compatibility—one of the factors of successful pollination. Pollen quality and grain size were analysed for two years on six male cultivars of A. arguta and one of A. chinensis var. deliciosa. Results showed high pollen quality, both with parameters above 80%. Pollen germination in vivo showed differences in pollen–stigma interactions. The highest positive interactions were observed for all female cultivar crosses with male ‘Nostino’ and ‘Rubi’ and the lowest one for A. chinensis var. deliciosa ‘Tomuri’. However, fruit set and average fruit weight were equally high in most of the combinations (fruit set above 75% for the majority of combinations). Some differences were noticed in the average seed number per fruit and weight. All tested male cultivars were able to fertilize tested female cultivars, but taking into account other characteristics such as pollen efficiency, some male cultivars seemed to be more proper for commercial orchards. Using A. chinensis var. deliciosa pollen seems to be unreasonable in tested conditions.


2020 ◽  
pp. 105-112
Author(s):  
T. Dilmaçünal ◽  
A.N. Yıldırım ◽  
B. Şan ◽  
F. Yıldırım ◽  
M.A. Koyuncu

2001 ◽  
Vol 69 (3) ◽  
pp. 1625-1629 ◽  
Author(s):  
C. Audibert ◽  
C. Burucoa ◽  
B. Janvier ◽  
J. L. Fauchère

ABSTRACT Helicobacter pylori virulence is associated with the presence of the cag pathogenicity island (PAI). Thecag PAI is involved in the ability to induce interleukin-8 (IL-8) secretion by human cells, which is implicated in the inflammatory response of the gastric mucosa to H. pyloriinfection. The aim of this study was to determine whether the genetic structure of the cag PAI is conserved and whether it is linked to IL-8 induction ability. Detection of specific markers (cagA, picB, cag13-cag14, virD4, and IS605) by PCR and dot blot hybridization and long-distance PCR determination of the presence of cagI, cagII, and the middle region of thecag PAI were performed on 153 strains isolated from adults suffering from ulcers (n = 79) or gastritis (n = 74). IL-8 induction ability was evaluated by coculture of the strains with HEp-2 cells. Eighty-three strains (54.3%) had an entire cag PAI, 12 strains (7.8%) had thecag PAI split in two, 49 strains (32%) had nocag PAI, and 9 strains exhibited other structural combinations. The presence of an entire cag PAI was statistically correlated with the presence of IS605(P = 0.006) and the ability to induce IL-8 secretion but not with clinical presentation of the infection. The structure of the cag PAI appears to be rather conserved and is related to the proinflammatory power of a strain. The existence of strains inducing IL-8 secretion regardless of the cag PAI structure suggests that this region is not the only requirement for IL-8 secretion.


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