INITIAL PRODUCTIVE PERFORMANCE OF COFFEE PROGENIES IN AN AREA INFESTED BY Meloidogyne paranaensis

In this study, we aimed to carry out a selection of Coffea arabica progenies in areas infested by Meloidogyne paranaensis in order to select materials that are resistant to this nematode, with desirable agronomic characteristics. The experiment was set on Guaiçara Farm, located in the Municipality of Piumhi – MG, in February 2012. Twenty-one coffee progenies were evaluated in the F5 generation and 5 commercial cultivars were used as a control. A randomized complete block design was used, with three replicates, totaling 78 plots, consisting of eight plants each. The spacing used was 3.00 x 0.50 m in the rows and between plants, respectively. The populations of M. paranaensis per gram of coffee roots, productivity (bags. ha-1), plant vigor, maturation cycle, maturation uniformity, coffee ranking by grain size (sieve 17 and above), and classification of mocha coffee were evaluated. It was concluded that progenies MG 0179-3-R1-151 and MG 0185-2-R2-132 are resistant to M. paranaensis and have good agronomic characteristics in an area naturally infested by this nematode, thus indicated for plantations in this situation. Nine progenies reveal tolerance/resistance characteristics to M. paranaensis. Termos para indexação: Coffea arabica, production, nematode, resistance, amphillo. PERFORMANCE PRODUTIVA INICIAL DE PROGêNIES DE CAFEEIRO EM áREA INFESTADA POR Meloidogyne paranaensis RESUMO: Objetivou-se neste trabalho selecionar progênies de Coffea arabica em área infestada resistentes a esse nematóide, com características produtivas desejáveis. O experimento foi instalado na Fazenda Guaiçara, situada no Município de Piumhi MG. Vinte e uma progênies de cafeeiro em geração F5 e cinco cultivares comerciais (testemunhas) foram avaliadas por meio da população de Meloidogyne paranaensis, produtividade de um biênio (sc.ha-1), vigor vegetativo, ciclo de maturação, uniformidade de maturação, classificação do café por tamanho do grão (peneira 17 e acima) e classificação do café moca. As progênies MG 0179-3-R1-151 e MG 0185-2-R2-132 apresentaram resistência a M. paranaensis e boas características agronômicas em área naturalmente infestada por esse nematoide, sendo indicadas para plantios nessa situação. Nove progênies apresentaram características de tolerância ao M. paranaensis. Termos para indexação: Coffea arabica, produção, nematoide, resistência, amphillo.

The main strategy for the management of phytonematodes is prevention, that is, to prevent the entry and dissemination of the nematode in the area it occurs through infested seedlings, contaminated soil adhered to machines and Initial productive performance of coffee ... 531 From the 42 C.arabica progenies in generation F 4 evaluated by Salgado et al. (2014), 21 progenies in the F 5 generation were planted in February 2012, together with five commercial cultivars used as controls (Table 1) in a randomized complete block design with three replicates, totaling 78 plots, consisting of eight plants each. The spacing used was 3.00 x 0.50 m between rows and between plants, respectively.
Phytosanitary management was carried out preventively or curatively, using chemical products, accompanying the seasonality of the occurrence of pests and diseases. The chemical control of the nematode in the area was not carried out, aiming at the identification and selection of progenies resistant to these pathogens.

Quantification of M. paranaensis population in coffee roots and population biological indicator test in the plot soil
Aiming the quantification of M. paranaensis population, root samples were removed in October 2015, after the first plant production, avoiding to hinder the initial development of coffee trees. The samples were collected at a depth of approximately 30 cm (Freitas et al., 2007), at four plot points (sub-samples), in the projection of the plant crown, forming a composite sample conditioned in a plastic bag. The nematode extraction from these samples occurred according to the Hussey and Barker (1973) method to obtain the suspension of second-stage juveniles and eggs (J2) of M. paranaensis, which were quantified using a counting slide under an inverted objective microscope.
The biological indicator test (Bioteste) used soil samples taken from each experimental plot in trays with 100-mL cells, duly identified according to the representative field plot. A 'Santa Clara' tomato seedling per cell was used as a biological indicator of M. paranaensis population in the plot soil. This biotest was evaluated by the quantification of M.paranaensis population (eggs + second-stage juveniles -J2) in tomato roots at 50 days of planting.

Progeny performance in the infested area
The agronomic characteristics evaluated in the first two harvests, 2014/2015 to 2015/2016, represent: production in liters of "bica corrida" coffee, considering an average yield of 480 liters of "farm coffee" for each 60-kg bag of processed coffee. implements and mainly runoff water from plots or areas already infested (SALGADO; REZENDE, 2014). Cultural, biological and chemical management have been used as a strategy to reduce the nematode population (GOLÇALVES et al., 1996). However, all these strategies have low efficiency when compared to genetic control, which has been shown to be more efficient and economically viable (ITO et al., 2008).
The sources of resistance are present in some species of the genus Coffea, such as Coffea canephora Pierre ex A. Froehner Coffea congensis A. Froehner (SERA et al., 2007) and Studies on the behavior of coffee genotypes in relation to Meloidogyne spp., in majority, have been conducted under greenhouse conditions. However, there is little research on genetically improved materials in areas infested with M. paranaensis (REZENDE et al., 2013). Even if it requires more time, the selection work carried out in the field is necessary and extremely important for breeding programs, since the data on the performance of coffee progenies become more reliable (OLIVEIRA et al., 2011). Salgado et al. (2014) verified that some genotypes obtained in the active germplasm bank (BAG-Café) of Empresa de Pesquisa Agropecuária de Minas Gerais -EPAMIG present promising initial behavior in an area infested by M. paranaensis in the municipality of Piumhi, Minas Gerais.
In this study, we aimed to carry out a selection of Coffea arabica L. progenies in areas infested by M. paranaensis in order to select materials that are resistant to this nematode, with desirable agronomic characteristics.

Research installation
The selected experimental area presents a high infestation of M.paranaensis, a species identified by electrophoresis (CARNEIRO and ALMEIDA, 2001). The area is located in the Southwest region of Minas Gerais, in the municipality of Piumhi, Fazenda Guaiçara, privately owned, located at 20° 25' 28,7" South latitude, 46° 1' 10,5" longitude and average altitude of 812 m, soil with clayey texture and flat terrain. The average annual temperature is 20.7°C.
After coffee processing in 2015 and 2016, a 300-g sample was passed through a set of sieves (8 to 13), and the material was retained in each sieve, determining the percentage of mocha grains (BRASIL, 2003); plant vigor, evaluated by assigning scores according to an arbitrary 10-point scale, with score 1 given to the worst plants, with very reduced plant vigor and marked degradation symptoms, and score 10 to plants with excellent vigor, more unveiled and with marked plant growth of productive branches, as suggested by Carvalho TABLE 1 -Progeny relation and genealogy in generation F5 and of the five commercial cultivars evaluated in the municipality of Piumhi -MG, in an area naturally infested by Meloidogyne paranaensis.

Nº
Progenies Origin  (1979). In 2016, in the evaluation of the maturation cycle, scores were assigned according to an arbitrary 5-point scale, in which 1 = early; 2 = average to early; 3 = average; 4 = average to late and 5 = late; for maturity uniformity, scores were assigned according to an arbitrary 4-point scale, where 1 = uniform; 2 = moderately uniform; 3 = moderately uniform and 4 = uniform. Data on the reproductive development of coffee plants and on progeny reaction to the nematode were submitted to analysis of variance by the statistical software SISVAR (FERREIRA, 2008). Initial productive performance of coffee ... 533 nematodes, bacteria, etc.), without significant damage to its production. On the other hand, the controls represented by susceptible commercial cultivars had low yield (Table 3), confirming the economic damage of this nematode. This marked reduction in yield indicates how much damage M. paranaensis can cause to susceptible cultivars, as a consequence of parasitism, with the destruction of the root system, which may cause general degradation.
Regarding vigor scores, the averages were grouped in two classes by the Scott-Knott test at 5% probability, with 10 treatments that showed higher scores. The most vigorous genotypes are 4, 5, 6, 10, 11, 12, 15, 21, 25 and 26, with average vigor scores ranging from 5.12 to 8.0 (Table 3). The susceptible controls obtained the lowest scores, on average, evidencing the impairment of their plant development in the presence of nematodes. In addition to influencing production, according to Carvalho et al. (2012) and Carvalho et al. (2008), plant vigor reduces, to a certain extent, coffee bienniality and is directly related to genotype yield and adaptability to the different edaphoclimatic conditions. Progenies 4, 10 and 11 showed a low M. paranaensis population in coffee roots, good plant vigor and high yield in the biennium. This indicates that these progenies have the potential for continuation in generation advance and/or backcrossing within the coffee breeding program of EPAMIG. The smallest M. paranaensis population in the roots of these progenies can be attributed to Amphillo, since this genetic material is a possible source of resistance to M. paranaensis. Salgado et al. (2014) identified F 4 plants derived from the crossing between 'Catuaí Vermelho', 'Amphillo' MR 2161 and 'Híbrido de Timor' UFV 408-01 as promising, potentially resistant to M. paranaensis and, therefore, important to the coffee breeding program. Silva et al. (2015) observe that progeny 5, from the cross of 'Catuaí Vermelho' and 'Amphillo' 2-161, whose plant in the F 4 generation supplied progeny 5 with seeds in this research, had a capacity for acclimatization to the water deficit, as evidenced by the maintenance of water status, gas exchange and better photochemical performance, culminating in higher yield. Studies of these genotypes in areas infested by other Meloidogyne species should be carried out, as there is the possibility of obtaining coffee cultivars with resistance to several rootknot nematode species (Boisseau et al., 2009).
From the detection of significant differences between treatments, the means were grouped by the Scott Knott test, at 5% probability. The data transformations (log(x)) and (√(x+1)) were used for data on nematode populations in coffee (PGR) and tomato roots (PGRBIOTESTE).
For the nematode population in coffee roots, 16 treatments had smaller egg and second-stage juvenile populations (J2). Commercial cultivars used as susceptible controls had a high nematode population (Table 2).
According to Salgado, Rezende and Nunes (2014), the plant resistance mechanism to nematodes prevents high reproductive rate from nematode and, consequently, besides not causing damage to the crop, they lead to a decrease in its population in the soil. This explains the results of the biotest, when compared with the evaluations of the nematode population in coffee roots.
The average yields estimated in the biennium 2014/2015 and 2015/2016 ranged from 20.25 sc ha -1 (treatment 16) to 82.60 sc ha -1 (treatment 11), and approximately 40% of the progenies had a performance higher than the global average, suggesting a resistance/tolerance of these progenies to M. paranaensis. Progenies 4, 5, 11 and 12 had an average yield of 251.30%, higher than the 5 susceptible controls (Table 3).
The superiority in progeny production, associated with M. paranaensis population in the roots, indicates a resistance behavior of progenies 4 and 11 and a tolerance behavior of progenies 5 and 12 since, according to Trudgill (1991), tolerance refers to the inherent or acquired capacity of a plant to support pathogen infection (fungus, viruses, Progenies MG 0179-3-R1-151 (5), originated from the cross between C. V. X Amphillo MR 2-161 and MG 0185-2-R2-132 (11), coming from the cross between C. V X. Amphillo MR 2-474, were classified as resistant by Pasqualoto (2015) and Peres (2013), respectively, corroborating the results obtained in this study. Pasqualoto (2015) evaluated progenies in infested areas and greenhouse environments, and Peres (2013) evaluated the reproductive factor of M. paranaensis and M. incognita, breed 1, in a greenhouse and compared the results with those obtained from areas infested with M. paranaensis.
Treatment 23 presents good yield and low nematode population in the roots, but with low vigor. However, Pasqualoto (2015) concluded that this progeny, MG 0179-1-R1-1051, from the cross between C. V. X Amphillo MR 2-161, is resistant to M. paranaensis.
Progenies 10, 18, 19 and 22 can be considered of intermediate performance, according to plant yield and vigor. Peres et al. (2017) concluded that plants of progenies MG 0179-1-R1-90, MG 0179-1-R1-89 and MG 0179-1-R1-775, from which seeds were obtained for treatments 10, 18 and 22 of this study, respectively, were resistant to the nematodes M. paranaensis and M. incognita. In the evaluation and selection of coffee plants, researchers seek an ideotype whose performance includes, besides other characteristics, high yield and percentage of grains classified in high sieves (FERREIRA et al., 2005). In general, increased grain size provides greater uniformity of the batch to be processed and directly influences the physical appearance of the product, which is desirable, mainly for use in espresso machines (FERREIRA et al., 2013). For this characteristic, it was observed that three groups were formed, and only 'Mundo Novo' IAC 379-19 was in the superior group; in the intermediate group, there were 6 treatments, with 5 progenies and 'Catuai Amarelo' IAC 62 and, in the inferior group, 19 treatments, with 16 progenies and 'MS Resplendor', 'Paraíso' MG H 419-1 and HT UFV 408-26.
Mocha beans originate under lack of fertilization conditions or even when fruit development occurs in one of the stores GASPARI-PEZZOPANE et al., 2005). Carvalho et al. (2009) define mocha beans as grains that have ovoid shape, with a crack in the longitudinal format. The evaluation of their average percentage in the biennium 2014/2016 had two classes, and only three progenies with percentages above the average (Table 4). In addition to the percentage of mocha, grain size (% sieve 17 and above) may have been affected by rain scarcity in the period, compromising plant nutrition, flower setting and fruit granulation. During this period, there was a water deficit of approximately 500 mm in relation to the historical average (Table 4).
As for the average maturity uniformity scores, two distinct groups were formed: 9 progenies and the controls 'Catuaí Amarelo' IAC 62, 'Mundo Novo' IAC 379-1, 'MS Resplendor', 'Paraíso' MG H 419-1 were in the first group, with average scores ranging between 1.82 and 2.89, classified as moderately uniform; the other 12 progenies and cultivar HT UFV 408-26 make up the other group, with average scores ranging from 3.00 to 3.96, classified as moderately uneven to uneven.

CONCLUSIONS
Progenies MG 0179-3-R1-151 and MG 0185-1-R2-132 were resistant to M. paranaensis and had good agronomic characteristics in an area naturally infested by this nematode, being indicated for plantations in this situation.
The high yield of progeny MG 0185-1-R2-132, above 80 sc/ha, evidences its great productive potential in areas infested with M. paranaensis.