scholarly journals Analysis of the Variability of Floral and Pollen Traits in Apple Cultivars—Selecting Suitable Pollen Donors for Cider Apple Orchards

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1717
Author(s):  
Alvaro Delgado ◽  
Muriel Quinet ◽  
Enrique Dapena

Most apple trees (Malus domestica Borkh.) are self-incompatible and fruit yield depends on cross-pollination between genetically compatible cultivars with synchronous flowering. Flowering intensity can vary strongly among years due to the biennial bearing habit of the cultivars. The knowledge of the phenological stages and floral and pollen characteristics is essential to select suitable pollen donors. We evaluated the phenotypic variability of flowering-related traits (i.e., flowering phenology, flowering intensity, pollen production and pollen quality) in 45 apple cultivars over two successive flowering seasons. Large phenotypic variability was found among the studied cultivars indicating that the local germplasm collection provides a good source of genetic and phenotypic diversity. However, low correlations were observed between floral biology traits and, consequently, the improvement in one trait seems not to affect other traits. Some of the cultivars such as ‘Perurico’ and ‘Raxila Dulce’ regularly produced copious amounts of high-quality pollen which can improve the pollen load dispersion leading to a most effective pollination process. We did not identify statistically significant correlations between pollen attributes and the biennial bearing phenomenon. The large variation in bloom dates from year-to-year observed under a typical Oceanic climate makes it advisable to combine cultivars in new plantings.

2010 ◽  
Vol 58 (5) ◽  
pp. 373 ◽  
Author(s):  
L. Baskorowati ◽  
M. W. Moncur ◽  
J. C. Doran ◽  
P. J. Kanowski

Melaleuca alternifolia (Maiden & Betche) Cheel is commercially important as the source of essential oil for the Australian tea tree-oil industry. Information on reproductive biology of M. alternifolia is important to the Australian breeding program directed at improving the quality and quantity of tea tree oil. Flowering in three geographically separated sites – two planted seed orchards and one managed natural population, all in NSW – was observed in the present study, with supporting data obtained from glasshouse-grown plants in Canberra. The majority of the work was conducted from 2004 to 2007, although the study also drew on some prior observations. M. alternifolia has spikes of flowers that open acropetally over a 6-day period. No strong separation of male and female phases was found in any individual flower; pollen was shed by 1.4 days after anthesis and the stigma reached peak receptivity 3–5 days after anthesis. Dichogamy and acropetal floral development may lead to geitonogamy. Flowering occurred during the months of October–November, with the peak in November, and was synchronous across all three sites. Flowering intensity and success in producing capsules appeared to be associated with total spring rainfall. Initiation of flowering in M. alternifolia appears to be correlated with daylength, or an environmental parameter closely correlated with daylength. Flowering intensity varied considerably among the years surveyed, sites and families, and appears to be promoted by a period of winter minimum temperatures below 5°C. In M. alternifolia, the morphological development of buds, flowers and fruit leading to the development of mature seed takes place over a period 16–18 months from flowering. M. alternifolia differed significantly in the number of viable seeds per capsule from individual trees, from 26 ± 3.8 to 57 ± 3.8 germinants.


2022 ◽  
Vol 175 ◽  
pp. 114303
Author(s):  
V.M.V. Cruz ◽  
D.A. Dierig ◽  
A. Lynch ◽  
K. Hunnicutt ◽  
T.R. Sullivan ◽  
...  

Plant Disease ◽  
2021 ◽  
Author(s):  
Dennis Katuuramu ◽  
Sandra Branham ◽  
Amnon Levi ◽  
Patrick Wechter

Cultivated sweet watermelon (Citrullus lanatus) is an important vegetable crop for millions of people around the world. There are limited sources of resistance to economically important diseases within C. lanatus, whereas Citrullus amarus has a reservoir of traits that can be exploited to improve C. lanatus for resistance to biotic and abiotic stresses. Cucurbit downy mildew (CDM), caused by Pseudoperonospora cubensis, is an emerging threat to watermelon production. We screened 122 C. amarus accessions for resistance to CDM over two tests (environments). The accessions were genotyped by whole-genome resequencing to generate 2,126,759 single nucleotide polymorphic (SNP) markers. A genome-wide association study was deployed to uncover marker-trait associations and identify candidate genes underlying resistance to CDM. Our results indicate the presence of wide phenotypic variability (1.1 - 57.8%) for leaf area infection, representing a 50.7-fold variation for CDM resistance across the C. amarus germplasm collection. Broad-sense heritability estimate was 0.55, implying the presence of moderate genetic effects for resistance to CDM. The peak SNP markers associated with resistance to P. cubensis were located on chromosomes Ca03, Ca05, Ca07, and Ca11. The significant SNP markers accounted for up to 30% of the phenotypic variation and were associated with promising candidate genes encoding disease resistance proteins, leucine-rich repeat receptor-like protein kinase, and WRKY transcription factor. This information will be useful in understanding the genetic architecture of the P. cubensis-Citrullus spp. patho-system as well as development of resources for genomics-assisted breeding for resistance to CDM in watermelon.


2020 ◽  
Vol 42 (5) ◽  
Author(s):  
Elias Emanuel Silva Mota ◽  
Carolina Ribeiro Diniz Boaventura Novaes ◽  
Luciana Borges e Silva ◽  
Lázaro José Chaves

Abstract Dipteryx alata Vogel (“baru tree”) is a fruit species native to the Brazilian Cerrado and presents a multiplicity of uses, constituting a priority species for domestication and cultivation studies. The objective of the current study was to characterize fruit and seeds of D. alata from several regions of the Brazilian Cerrado biome to support strategies for ex situ conservation and utilization of the genetic variability of the species. Fruits were collected from 25 subpopulations, sampling six mother plants per subpopulation, with collection of at least 25 fruits per plant. The physical trait data of the fruits and seeds were submitted to descriptive analysis, analysis of variance and correlation among traits. There was significant variation for all traits among subpopulations and among individuals within subpopulations. The highest proportion of variability was observed among individuals within subpopulations. The phenotypic differentiation among subpopulations was higher for fruit traits compared to seed traits. The correlation analysis showed the existence of significant correlations for most of the traits pairs in the different hierarchical levels. It was concluded that D. alata presents phenotypic variability to support germplasm collection programsand formation of base populations for breeding programs, recommending the sampling in several locations to ensure an adequate representativeness of the phenotypic variability.


2021 ◽  
pp. 41-48
Author(s):  
E. Barcanu ◽  
O.L. Agapie ◽  
I. Gherase ◽  
B.E. Tănase ◽  
G. Negosanu ◽  
...  

Author(s):  
Thomas Wöhner ◽  
Ofere Francis Emeriewen ◽  
Monika Höfer

AbstractDiplocarpon coronariae causes apple blotch, which results in significant economic losses. Resistance to apple blotch in commercial apple cultivars has not been reported in recent literature. The Malus germplasm collection from the Fruit Genebank of the Julius Kühn-Institut that is maintained in Dresden, Germany consists of 516 accessions of about 49 Malus species. This apple gene pool was evaluated for resistance to Diplocarpon coronariae. A four-year field survey was subsequently followed by artificial inoculation of field-selected accessions. Fifteen accessions that represent nine different species and hybrids were confirmed to be highly resistant following a repeated inoculation assay in the laboratory. The results from this investigation is of high interest to breeders for future apple breeding programmes and investigations of resistance to Diplocarpon coronariae.


2011 ◽  
Vol 33 (No. 4) ◽  
pp. 131-139 ◽  
Author(s):  
J. Blažek ◽  
J. Křelinová

 In an orchard trial that was established in the spring of 1999 on M 9 rootstock at the spacing of 4 × 1 m, eleven new apple cultivars bred in Holovousy (Angold, Julia, Nabella, Primadela, Produkta, Resista, Rubinstep, Rucla, Selena, Vysočina and Zuzana) were evaluated in comparison with three standard varieties (Gala, Golden Delicious and Jonagold) and another two with resistance to scab (Rosana and Topaz). In the first three years, the incidence of scab and mildew was evaluated under limited chemical protection. In 2000–2005 on each of 10 randomly selected trees of each cultivar, the time of flowering and optimum harvest ripening were recorded, flower set and fruit sets were rated, yield per tree and weight of 10 fruit samples were measured. Trunk diameter was measured between 2002 and 2005. The early summer apple Julia had the healthiest state and it was recommended for organic growing. Selena was the most precocious, the least vigorous and had the highest crop efficiency. The highest annual yields per tree were recorded with Produkta, but this cultivar had the highest proportion of trees with biennial bearing. Primadela achieved the highest cumulative yields, whereas Angold brought the largest fruits on average. With the obtained results, the evaluated cultivars were characterised by some important features or recommendations for growers.  


Plants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 206 ◽  
Author(s):  
Pasquale Chiaiese ◽  
Giandomenico Corrado ◽  
Maria Minutolo ◽  
Amalia Barone ◽  
Angela Errico

Research on plant antioxidants, such as ascorbic acid (AsA) and polyphenols, is of increasing interest in plant science because of the health benefits and preventive role in chronic diseases of these natural compounds. Pepper (Capiscum annuum L.) is a major dietary source of antioxidants, especially AsA. Although considerable advance has been made, our understanding of AsA biosynthesis and its regulation in higher plants is not yet exhaustive. For instance, while it is accepted that AsA content in cells is regulated at different levels (e.g., transcriptional and post-transcriptional), their relative prominence is not fully understood. In this work, we identified and studied two pepper varieties with low and high levels of AsA to shed light on the transcriptional mechanisms that can account for the observed phenotypes. We quantified AsA and polyphenols in leaves and during fruit maturation, and concurrently, we analyzed the transcription of 14 genes involved in AsA biosynthesis, degradation, and recycling. The differential transcriptional analysis indicated that the higher expression of genes involved in AsA accumulation is a likely explanation for the observed differences in fruits. This was also supported by the identification of gene-metabolite relations, which deserve further investigation. Our results provide new insights into AsA differential accumulation in pepper varieties and highlight the phenotypic diversity in local germplasm, a knowledge that may ultimately contribute to the increased level of health-related phytochemicals.


2018 ◽  
Vol 46 (1) ◽  
pp. 190-196 ◽  
Author(s):  
Daniela MADRID ◽  
Eduardo SALGADO ◽  
Gabriela VERDUGO ◽  
Pablo OLGUÍN ◽  
Dimitrios BILALIS ◽  
...  

Coastal/lowland quinoa ecotype is an important source of germplasm due to its cultivation in cold-temperate and high latitude areas. However, the interaction of its morphological traits and yields to define breeding criteria is unknown. The present study was designed to characterize the phenotypic diversity of twelve coastal/lowland quinoas using sixteen standardized morphological descriptors under rainfed conditions in central Chile. Complementary analysis of uni- and multi- variate tools allowed a fuller understanding of interrelationships within quinoa germplasm. Through the analysis of frequency distribution, it was possible to determine that genotypes were characterized by plants having low height and medium grain yield. Cluster analysis revealed that plant morphological variables were independently grouped from grain yield components. Additionally, principal component analysis (PCA, 74.8% of total variation data), revealed the existence of three outstanding genotypes (QC01, QC02 and QC05) that were distantly located from the average dispersion of entire germplasm collection. These genotypes were associated with grain yield components, allowing the identification of two groups of high yield (VI and VII), which yielded 3337.7 and 3052.0 kg ha-1, respectively. The data set presented in this study is the first report of coastal/lowland quinoas assessed in central Chile and could assist the development of breeding programmes in cold-temperate areas having similar agro-climatic conditions.


1985 ◽  
Vol 33 (5) ◽  
pp. 543 ◽  
Author(s):  
BM Potts ◽  
JB Reid

E. risdonii is a rare Tasmanian endemic which occurs as a series of small disjunct populations within a more-or-less continuous population of a closely related species, E. amygdalina. In localized areas (e.g. Risdon, Tasmania), patches of high phenotypic diversity are encountered, with individuals encompassing the complete phenotypic range between these two species. Progeny trials indicate a large heritable component to this variation. Open-pollinated progenies from intermediate mothers exhibit greater variability than those from either pure species, which strongly suggests that these intermediate phenotypes are a result of hybridization. Progenies from pure species mothers near a hybrid swarm are more variable than those from pure stands. There is a greater proportion of seedlings which match the artificially produced F1 in open-pollinated progenies from E. amygdalina than from E. risdonii mothers. In addition, progenies from intermediate mothers show a bias toward E. risdonii types, which implies that they are predominantly outcrossing to E. risdonii. This evidence suggests an asymmetrical flow of genes by pollen migration from E. risdonii into the hybrid swarm and surrounding E. amygdalina. Little difference in seedling vigour or mortality occurred between seedlings from the various parental phenotypes, although differences in seed output per capsule and germination were apparent. The specific identity of E. risdonii and E. amygdalina is usually maintained in parapatry by a range of mechanisms including their specific ecological preference, reduced hybrid fitness and differences in flowering phenology. The reasons for the major zones of hybridization occurring at boundaries on ridge tops as opposed to those on the dry slopes are discussed.


Sign in / Sign up

Export Citation Format

Share Document