‘SCS449 Lorenzo’: New somatic mutant apple cultivar with early harvest and resistant to glomerella leaf spotAbstract:
SCS449 Lorenzo is a spontaneous somatic mutation originated from the apple cv. Condessa, an early-season cultivar with low chilling requeriment. The new cultivar exhibits genetic resistance to glomerella leaf spot, a major summer disease in Brazil that is difficult and costly to control. The fruits mature between late December to early January depending on the production region. The percentage of red skin coverage (74%) fruit quality attributes, maturation characteristics and plant morphology are similar to those of ‘Condessa’. The mutation, therefore, reduces the need for fungicide applications for disease control while maintaining high fruit yield.
Index terms
Malus x domestica; fruit quality; disease; Colletotrichum
Resumo:
A ‘SCS449 Lorenzo’ é uma mutação somática espontânea originada da cultivar de maçã Condessa, uma cultivar precoce com baixa necessidade de frio. A nova cultivar apresenta resistência genética à mancha foliar glomerella, uma importante doença de verão no Brasil, de difícil e custoso controle. Os frutos amadurecem entre o final de dezembro e o início de janeiro, dependendo da região produtora. A porcentagem de cobertura da casca vermelha (74%), os atributos de qualidade dos frutos, as características de maturação e a morfologia da planta são semelhantes aos da ‘Condessa’. A mutação, portanto, reduz a necessidade de aplicações de fungicidas para o controle da doença, mantendo a alta produtividade.
Termos para indexação
Malus x domestica; qualidade fruto; doença; Colletotrichum
Introduction
Between the 2008 and 2021 harvests, the ‘Gala’ group accounted, on average, for 57.5% of Brazil’s apple production, while the ‘Fuji’ group accounted for 36.5%. The remaining cultivars, including Condessa, Cripps Pink, Daiane, Eva, and Monalisa accounted for just 6.0% (FAORO, 2022).
This indicates that the cv. Condessa is still planted in limited areas, resulting in low production.
The primary factors contributing to this include: a) the short marketing window for its fruit, before the higher-quality fruit from ‘Gala’ group start to dominate the market in late January; b) the short life of approximately 1.5 months for its fruit (EPAGRI, 2013); and c) its susceptibility to glomerella leaf spot (GLS) (DENARDI; CAMILO, 1998), a disease caused by a complex of Colletotrichum sp., which is a challenge and costly to manage during the summer.
‘Condessa’ and ‘Eva’ are most planted as early- season apple cultivars in Brazil, needing fewer chilling hours to break bud dormancy, allowing their fruit to ripen between December and January - at least a month earlier than ‘Gala’ apples. As a result, they can be cultivated in warmer regions, and fruit are available during the peak pricing season (ARGENTA et al., 2015). Small family growers in Southern Brazil have produced most ‘Condessa’ and ‘Eva’ apple fruit.
‘Eva’ and its mutations, cv. Condessa and now its mutation ‘SCS449 Lorenzo’ are the main cultivars with early harvest (between December and January) and that produce fruit of good commercial quality in Southern Brazil. They are excellent options for small and medium producers, who can obtain substantial profits in this commercial “window”. Currently, apple prices are higher (ARGENTA et al., 2015), which contributes positively to these profits.
During this short marketing period, a shortage of fresh fruit is common, with the availability of fruit from the ‘Fuji’ group and, to a lesser extent, those from the ‘Gala’ group, both of which are stored for approximately 9 to 11 months respectively. As a result, they have less flavor, juiciness and firmness of the pulp and do not exhibit the “fresh” appearance of having just been harvested.
‘SCS449 Lorenzo’, a spontaneous somatic mutant of ‘Condessa’, offers a significant advantage due to its genetic resistance to GLS. This resistance reduces production cost, necessitating fewer fungicide applications and lowers associated spraying expenses.
Additionally, minimizing early leaf fall allows greater reserve accumulation in the buds, thereby enhancing budding and fruit development in subsequent harvests.
Furthermore, the decreased reliance on pesticides lessens potential environmental impacts and improves food security. As a result, Condessa’ is likely to be supplanted by the new cultivar ‘SCS449 Lorenzo’.
This work aims to provide information on phenological characteristics of the plant, the fruit quality and the genetic resistance to GLS of the new ‘SCS449 Lorenzo’ apple cultivar.
Materials and Methods
The apple plant that gave rise to the new mutant strain ‘SCS449 Lorenzo’ was identified in January 2015 in a small apple orchard (1ha) of ‘Condessa’ grafted on ‘M.9’ (interstem)/’Marubakido’ on the property of Mr. Sérgio Castellani. This orchard was planted in 2007 in Linha Caixa D’Água locality, of Caçador municipality, Santa Catarina State, Brazil.
The selection methods employed to develop ‘SCS449 Lorenzo’ adhered to the protocols outlined by Faoro (2018), initially utilizing the Continuous Pruning Method (CPM) on the original ‘Condessa’ plant. In the subsequent generations of asexual reproduction, both the Grafting Method (ME) and the CPM were implemented.
The original generation of ‘Condessa’ is designated by the symbol M0Vx. From this cultivar, the first spontaneous somatic mutant, designated as ‘SCS449 Lorenzo’ (generation M1Vx), was identified. Therefore, “Mx” indicates the generations in which a new mutant arose from the original cultivar. In contrast, the “Vx” indicates the generations of asexual reproduction (through grafting and pruning) within the same Mx mutant generation. The value of “x” increases by one unit with each new budding that results in primary, secondary and tertiary branches.
Segments from mutant tertiary branches (M1V3) originating from the original ‘Condessa’ plant, containing two to three buds, were grafted in July 2015 onto three adults ‘Castel Gala’/’M.9’/’Marubakaido’ plants on the same commercial orchard described above.
This process yielded generations M1V4, M1V5 and M1V6 over the following years. In 2017, secondary branches were collected from one of these plants and grafted onto adult ‘Castel Gala’/’M.9’/’Marubakaido’ plants, leading to the development of generations M1V6, M1V7 and M1V8.
On July 2019,segments of M1V7 branches were collected and grafted onto 20 adult plants of ‘Castel Gala’/’M.9’/’Marubakaido’ plants located on the producer’s property, as well as onto seedlings of ‘M.9’/‘Marubakaido’ at Epagri/ Caçador Experimental Station “José Oscar Kurtz” (CST), which were taken to the field on September 2020 to produce the M1V8 and M1V9 generations.
The harvested fruit were held at 0.5 °C and 95% relative humidity until they were evaluated for maturity and quality (Table 1).
The quantity and quality of the fruit evaluated were in the M1V5, M1V6, M1V7 and M1V8 generations regarding the following characteristics: a) fresh mass of the fruit, considering samples of fruit from the plants selected and evaluated each year; b) samples of 25 fruit were evaluated for flesh firmness (lb), titratable acidity (%) and total soluble solids (°Brix); c) starch index using scores from 1 (cross section of the flesh stained by the iodine-starch complex indicating high starch content and immature fruit) to 9 (cross section of the flesh not stained by the iodine-starch complex indicating starch content close to zero, indicating ripe fruit), according to the methodology described by Argenta et al., (2020).
The relative surface area of the fruit (% coverage) with reddish coloration was determined visually in relation to overall surface area. The small non-reddish dots or lines between the red stripes were added to the effectively red areas.
For comparative purposes, physicochemical measurements were used and the quality of ‘SCS441 Gala Gui’ fruits are averages obtained in five harvests (2016/2017 to 2020/2021), and for ‘Condessa’ are those obtained in this work (Table 1) and those cited by Denardi and Camilo (1998) (Table 3).
Resistance tests to glomerella leaf spot (GLS) were performed on branches from the M1V6 and M1V7 (12/17/2018) to M1V9 (03/16/2021) generations, using different numbers of isolates and inoculum concentrations(Table 2).
Isolates from the Colletotrichum spp. group were obtained in the following municipalities: Água Doce, Caçador, Fraiburgo, Papanduva, Pinheiro Preto, São Joaquim and Tangará, in SC state; in Vacaria and Veranópolis, in RS state; and in Palmas, in PR state. These collected fungi are stored at Epagri/Caçador Experimental Station “José Oscar Kurtz” in Caçador, SC, in the Phytopathology Laboratory. Most of the species of Colletotrichum isolates were C. chrysophilum (formerly C. fructicola) and, to a lesser proportion, C. nymphaeae.
For inoculation of GLS, branches measuring 35 to 40 cm in length and containing young leaves at their apex were collected. The branches were then washed in water, dried with paper towels and placed in 1.0 L plastic containers containing a 500 ml solution of water with 2.5% refined sugar. They were then taken to the inoculation chamber with a relative humidity of 95%, a temperature of 23°C + 0.5°C, and a photoperiod of 12 hours of darkness followed by 12 hours of light of one day of acclimatization. After this period, the branches were inoculated with isolates of Colletotrichum spp. and kept under the same conditions mentioned for 8 and 10 days.
The assessment of the severity of GLS in the leaves of the samples followed the diagrammatic scale of Moreira et al. (2019), considering the following classification: a) genotype considered resistant if its leaves do not express any symptoms of the disease or have symptoms in less than 0.5% of the affected leaf area; b) moderately resistant if its leaves express symptoms of severity affecting 0.5% to 20% of the leaf area; c) and susceptible if its leaves express severity greater than 20%, under controlled conditions.
Results and Discussion
The cv. Condessa was obtained from the cross between ‘Gala’ x Malus41 and was launched in 1998 by Epagri/ Caçador Experiment Station (DENARDI;CAMILO, 1998). It is characterized by low hours of chilling requirement (HF), requiring 400 to 450 h < 7.2°C or 700 to 900 UF from the Modified North Carolina Method. This quality was partially inherited from ‘Anna’, a parent of Malus 41, also a selection of very low chilling requirement (300 HF) (ANDERSEN,2000).
It is assumed that the new cultivar SCS449 Lorenzo, being a mutation of ‘Condessa’, has the same requirement for winter chilling, that is to say a low winter chilling. Cultivars with low winter chilling requirements, such as these two, have a higher effective temperature (up to 15°C) to overcome dormancy(PUTTI et al., 2003).
Therefore, they have the potential to be cultivated in areas with an average number of winter cold hours, such as the region of Itaiópolis, SC.
The morphological characteristics of the plants of the new cv. SCS449 Lorenzo are similar to those of the cv. Condessa. They have low to medium vigor (semi-dwarf ) and have open branches. They have a semispur fruiting habit, bearing fruit on lateral spurs and along one-year-old branches(DENARDI; CAMILO, 1998).
The one-year-old branches, brown in color, have medium to long internodes, medium pubescence and a low number of lenticels.
The leaf blade in position on the branch is horizontal, short in length and medium in width, with medium color and a serrated margin type 1 with medium pubescence on the underside. The petiole has medium anthocyanin coloration from the base. The flower is dark-pink with small petals, arranged separately. The stigmas are usually longer than the anthers.
The six-year average data (2018 to 2024) indicates that ‘SCS449 Lorenzo’ begins flowering on August 21, reaches full bloom by August 31 and ends flowering on September 10, which is similar to the timing of the cv. Condessa. Furthermore, the flowering intensity for ‘SCS449 Lorenzo’ is comparable to that of ‘Condesa.’ These observations suggest that the new cv. SCS449 Lorenzo retains the low chilling requirement characteristics necessary for breaking bud dormancy, similar to those of cv.Condesa.
The on-tree fruit ripening of ‘SCS449 Lorenzo’ follows a pattern similar to that of ‘Condessa’: the harvest window extends from late December to the first ten days of January, varying by winter climate in Southern Brazil. Consequently, they are typically harvested about 20 to 40 days earlier than apples from the ‘Gala’ group (GONÇALVES et al., 2017).
Immature fruit have little anthocyanin coloration. When fully mature, the fruit are medium- sized and ellipsoidal in shape (Figure 1). The epidermis shows either a absence or a weak stripe, and there is no bloom or oiliness, which is also minimal.
The background coloration is yellowish. The average coverage of the striped red surface coloration is good, with the stripes narrow to medium in width. The russeting area in the peduncular cavity is weak and is absent on the fruit sides. The number of lenticels is medium, and their size is small. The peduncle is short and medium in thickness. The flesh is firm to medium firm, with a light cream color, crunchy moderately juicy, and sweet.
The fruit must be marketed promptly after harvest, as they cannot withstand more than 1.5 months in cold storage (EPAGRI, 2013). The early harvest and appealing appearance of ‘SCS449 Lorenzo’ provide a significant commercial advantage allowing for better prices between early and late January, prior to the harvest of ‘Gala’ group cultivars. After this, the price of ‘Lorenzo’ is likely to decrease due to the better quality of the ‘Gala’ fruit.
For ‘SCS449 Lorenzo’ and ‘Condessa’, respectively, the flesh firmness is of 17.5 lb and 17.5 lb, the total soluble solids content SSC is of 13.2% and 13.3% and the starch is of 7,8 and 7,8 (Table 1), indicating that the mutation did not alter these quality variables.
The SSC of ‘SCS449 Lorenzo’ is within the expected range for ‘Condessa’ (12.5 ~ 13.0), as cited by Denardi and Camilo (1998).
The average mass of the fruit from ‘SCS448 Lorenzo’ is 125.1 g (Table 1) which is comparable to the range cited by Denardi and Camilo (1998) for ‘Condessa’ (110~120 g).
The minor variation can be attributed to the management practices implemented in the plants, including thinning, fertilization, and climate fluctuations over the years. The data obtained indicate that there has been no significant change in the weight and size of the fruit from ‘SCS448 Lorenzo’ in comparison to that of ‘Condessa’.
The area of red-striped color on the fruit surface is similar between the fruit of ‘SCS449 Lorenzo’ (74%) and ‘Condessa’ (71%) (Table 1). Even so, most of the fruit from both cultivars were classified within Class 1 (CAT 1) based solely on their red-colored area (MAPA, 2006). In this study fruit were harvested in advanced maturity (Table 1).
Therefore, the percentage of red coloration may be lower if the fruit will be harvested in early stage of maturity (Table 1).
The ‘SCS449 Lorenzo’ fruit exhibit an appealing commercial appearance (Figure 2) and good organoleptic quality for fresh consumption.
The area of red-striped color on the fruit surface is similar for both ‘SCS449 Lorenzo’ (71%) and ‘Condessa’ (68%) (Table 1). Even so, most of fruit of both cultivars fell into Class1 (CAT 1) when only the area of red-color of the fruit is considered for this classification (MAPA, 2006). These percentages would possibly be lower if the harvest will were done at the optimum maturity, since the fruit were harvested an advanced maturity stage (Table 1).
The cv. Condessa is moderately resistant to apple scab (Venturia inaequalis) and powdery mildew (Podosphaera leucotricha), and susceptible to glomerella leaf spot (Colletotrichum spp. complex) (DENARDI;CAMILO, 1998).
The new cv. SCS449 Lorenzo, developed from the selection of spontaneous somatic mutation from a ‘Condessa’ plant, is characterized by its genetic resistance to glomerella leaf spot (GLS). Genetic bases for resistance to this disease is governed by a single homozygous recessive gene pair (cg cg) (KATSURAYAMA et al., 2001; LIU et al., 2016; LIU et al., 2017). Among the two ‘Condessa’ parents, Gala’ is susceptible (DENARDI; CAMILO, 1998) while there is no information whether Malus 41 was resistant or susceptible to GLS, as it was eliminated just after making the crossing with cv. Gala (FREDERICO DENARDI, personal information,2021).
Although as genetic resistance to GLS is controlled by only a pair of genes, making it theoretically easier to overcome, it is believed that it may be a case of durable resistance. This assumption is supported by cv. Fuji, which has been cultivated in Brazil for over 50 years without any reported that loss of its resistance to GLS.
Perhaps some minor genes (DANTAS et al., 2003; DANTAS et al., 2005) or pyramided genes play a role in the genetic control of this disease.
Another explanation for the duration of this resistance is the continuous application of protective fungicides to control other diseases, such as scab and marssonina (Marssonina spp.), which also help to reduce the inoculum of Colletotrichum spp that cause GLS (OGOSHI et al., 2020).
Consequently, this practice reduces the likelihood of survival for mutant isolates capable of overcoming genetic resistance to GLS.
In controlled laboratory inoculations, using isolates of Colletotrichum spp. collected in different locations, showed that the new cv.SCS449 Lorenzo presents immunity-type resistance to GLS, as no symptoms of the disease were observed on the leaves. A similar reaction was observed with cv. SCS441 Gala Gui, while ‘Maxi Gala’ and ‘Gala Real’ exhibited susceptibility (Table 2).
Results obtained by inoculations with Colletotrichum spp. for testing resistance in apple cultivars under controlled conditions (Caçador, Santa Catarina, State).
The main characteristics of the new cv.SCS449 Lorenzo are described in Table 3, in comparison with its parent cv. Condessa and cv. SCS441 Gala Gui.
‘SCS449 Lorenzo’ is registered in MAPA/ National Register of Cultivars under no.49,196.
It is protected by Mapa/National Service for the Protection of Cultivars under n°20240053 for the period from 26/01/2024 to 26/01/2042, in the name of Epagri (maintainer) and the apple grower Sérgio Castellani. Therefore, it can only be multiplied under license from Epagri.
Conclusions
The cultivar SCS449 Lorenzo is a spontaneous somatic mutant of ‘Condessa’ that exhibits a genetic resistance to glomerella leaf spot, caused by Colletotrichum spp.complex.
The fruit quality and maturation characteristics, as well as the morphological traits of the plants are similar to those of ‘Condessa’.
‘SCS449 Lorenzo’ emerges as a promising option for producing early, high-quality apple fruit, particularly in regions with milder winter conditions (400~450h < 7.2°C) and situated at sea altitudes of less than 900m.
Acknowledgments
We thank Mr. Lourenço Faoro (in memorium) and Mr. Lorenzo Faoro Schimidt, respectively father and grandson of the first author, for being the source of inspiration for the name of the cultivar Lorenzo.
References
- ANDERSEN, P.C. Low-chill apple cultivars for North Florida and North Central Florida Gaisnesvile: UF/IFAS Extension/, 2000. 8p. (Series HS764). https://doi.org/:10.32473/edis-mg368-2009
-
ARGENTA, L.C.; AMARANTE, C.V.T.do; BETINELLI, K.S.; BRANCHER, T.L.; NESI, C.N.; VIEIRA, M.J. Comparison of fruit attributes of ‘Fuji’ apple strains at harvest and after storage. Scientia Horticulturae, New York, v.272, 2020. https://doi.org/10.1016/j.scienta.2020.109585
» https://doi.org/10.1016/j.scienta.2020.109585 -
ARGENTA, L.C.; VIEIRA, M.J.; SOUZA, F.D.; PEREIRA, W.S.P.; EDAGI, F.K. Diagnóstico da qualidade de maçãs no mercado varejista brasileiro. Revista Brasileira de Fruticultura, Jaboticabal, v.37, n.1, p.48-63, 2015. https://doi.org/10.1590/0100-2945-047/14
» https://doi.org/10.1590/0100-2945-047/14 - DANTAS, A.C.M.; VIEIRA, E.A.; NODARI, R.O.; KATSURAYAMA, Y.; BONETI, J.I. Classificação e estudo da herança de resistência Colletotrichum gloeosporioides, agente causador da mancha foliar em macieira. In: CONGRESSO BRASILEIRO DE GENÉTICA, 51, 2005, Águas de Lindoia. Anais [...] Águas de Lindóia: Sociedade Brasileira de Genética, 2005.
- DANTAS, A.C.M; BONETI, J.I.S.; KATSURAYAMA, Y.; NODARI, R.O. Herança da resistência da Mancha Foliar (Colletotrichum gloeosporioides Penz.) em macieira. In: CONGRESSO BRASILEIRO DE MELHORAMENTO DE PLANTAS, 2., Porto Seguro, 23 a 26 de abril de 2003. Anais [...] Porto Seguro: Sociedade Brasileira de Melhoramento de Plantas, 2003.
-
DENARDI, F.; CAMILO, F. Epagri 408-Condessa: nova cultivar de macieira de baixa exigência em frio hibernal. Agropecuária Catarinense, Florianópolis, v.11, n.2, p.12-5, 1998. https://doi.org/10.52945/rac.v11i2.1660
» https://doi.org/10.52945/rac.v11i2.1660 -
DENARDI, F.; CAMILO, F.; KVITSCHAL, M.V. SCS417 Monalisa: cultivar de macieira com boa adaptação climática no Sul do Brasil e resistência múltipla a doenças. Agropecuária Catarinense, Florianópolis, v.26, n.1, p.56-62, 2013. https://doi.org/10.52945/rac.v26i1.599
» https://doi.org/10.52945/rac.v26i1.599 - EPAGRI. Catálogo de cultivares 2013/2014 Florianópolis: Epagri/GMC, 2013. 42p.
- FAORO, I.D. (org.). Maçãs do grupo ‘Gala’ no BrasilFlorianópolis: Epagri, 2022. 304p.
- FAORO, I.D. Seleção de mutantes espontâneos de macieira. Florianópolis: EPAGRI, 2018. 40p. (Boletim Técnico, 183).
-
GONÇALVES, M.W.; ARGENTA, L.C.,MARTIN, M.S.de. Maturity and quality of apple fruit durinig the harvest period at apple industry. Revista Brasileira de Fruticultura, Jaboticabal, v.39, n.5, 2017. https://doi.org/10.1590/0100-29452017825
» https://doi.org/10.1590/0100-29452017825 - KATSURAYAMA, Y.; TSUCHIYA, S.; BONETI, J.I.S. Herança da resistência das macieiras à mancha da Gala (Colletotrichum goeosporioides). Fitopatologia Brasileira, Brasília, v.26, p.409, 2001.
-
LIU, Y.; LAN, J.; WANG, C.; LI, B.; JUNZHU, J.; LIU, C.; DAI, H. Investigation and genetic mapping of a Glomerella leaf spot resistance locus in apple. Plant Breeding, Chichester, v.136, p.119–25, 2017. https://doi.org/10.1111/pbr.12399
» https://doi.org/10.1111/pbr.12399 -
LIU, Y.; LI, B.; WANG, C.; LIU, C.; KONG, X.; ZHU, J.; DAI, H. Genetics and molecular marker identification of a resistance to glomerella leaf spot in apple. Horticultural Plant Journal, Amsterdam, v.2, n.3, p.121–5, 2016. https://doi.org/10.1016/j.hpj.2016.06.002
» https://doi.org/10.1016/j.hpj.2016.06.002 -
MAPA. Regulamento técnico de identidade e qualidade da maçã Instrução Normativa, 5. Brasília, 2006. Disponível em: http://sistemasweb.agricultura.gov.br/sislegis/action/detalhaAto.do?method=visualizarAtoPortalMapaechave=805793610 Acesso em: 10 jun. 2019.
» http://sistemasweb.agricultura.gov.br/sislegis/action/detalhaAto.do?method=visualizarAtoPortalMapaechave=805793610 -
MOREIRA, R.R.; DUARTE, H.da S.; MIO, L.L.M.D. Improving accuracy, precision and reliability of severity estimates of Glomerella leaf spot on apple leaves using a new standard area diagram set. European Journal of Plant Pathology, Dordrecht, v.153, p.975-82, 2019. https://doi.org/10.1007/s10658-018-01610-0
» https://doi.org/10.1007/s10658-018-01610-0 - OGOSHI, C.; MONTEIRO, F.M.; PINTO, F.A.M.F.; PERAZZOLI, V.; CARDOSO, D.A. Performance of fungicides on the management of Glomerella leaf spot in Southern Brasil. Plant Pathology and Quarentine, Chiang Raí, v.10, n.1, p.144-51, 2020.
-
PUTTI, G.L.; PETRI, J.L.; MENDEZ, M.E. Temperaturas efetivas para a dormência da macieira (Malus domestica Borkh). Revista Brasileira de Fruticultura, Jaboticabal, v.25, n.2, p.210-2, 2003. https://doi.org/10.1590/S0100-29452003000200006
» https://doi.org/10.1590/S0100-29452003000200006
Edited by
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Scientific Editor
Alexandre Pio Viana
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Associate Editor
Willian Krause
The data that support the findings of this study are available from the corresponding author, Faoro, I.D., upon reasonable request.
