Journal of Agricultural Science and Technology A 3 (2013) 126-130 Earlier title: Journal of Agricultural Science and Technology, ISSN 1939-1250

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Physiological and Phytosanitary Potentials of Coriander and Radish Seeds Jucilayne Fernandes Vieira, Francisco Amaral Villela, Orlando Antonio Lucca Filho and Raifer Simões Campelo Department of Plant Science-Sector of Science and Seed Technology, Federal University of Pelotas (UFPel), Pelotas, RS 96001-970, Brazil Received: November 15, 2012 / Published: February 20, 2013. Abstract: Information on seed vigor of the vegetable crops is always important and necessary due to the increasing demand of high quality seeds for sowing and high-value commercial. The cultivation of these species, conducted intensively, should be established with seed high potential physiological and health for the development of a more productive and sustainable agriculture. The present study was conducted to evaluate the potential physiological of seed lots of radish and coriander. The experiment was conducted at the laboratory of seed analysis and greenhouse of the plant science department of the Federal University of Pelotas in South Brazil. Four radish seed lots, cultivar “Saxa”, and four coriander seed lots, cultivar “Verdão” were used. Germination seed test, first count of germination, accelerated aging test, electrical conductivity and seedling emergence were used to evaluate the physiological quality of the lots. The experimental design was completely randomized design with five replications. Means were compared by Tukey test. The accelerated aging test was the most efficient test in assessing the physiological quality for both lots of radish seeds and coriander and this test provide coherent results with seedlings emergence. Key words: Radish (Raphanus sativus L.), coriander (Coriandrum sativum L.), vegetable crops, seed quality, seed vigor.

1. Introduction Vegetable seeds have a high commercial value, thus a lot of information about seed vigor are always important. The cultivation of these species, conducted intensively, should be established with seed of high physiological potential and seed health [1]. Researches talking about vegetable seeds have shown significant development in Brazil since the beginning of the 1990s, but papers are still less frequent than those conducted with species of other crops. It is true that many vegetable crops are grown, but each one has its own peculiarity, and the volume of available knowledge is not enough to the importance of this subject [2]. There are increasing demands on high quality seeds for the establishment of more productive and sustainable agriculture, and it is growing also the

Corresponding author: Jucilayne Fernandes Vieira, Ph.D., research fields: seed science and technology. E-mail: [email protected].

importance of monitoring each stage of the seed production process of the seed industry [3]. The radish crop (Raphanus sativus L.) is an annual vegetable crop grown mainly on small farming and in areas of green belts of the country [4]. It has shorter cycle among vegetables; and because of this, radish becomes an excellent choice for the small producer [5]. It has considerable economic importance, but it is still produced and consumed in volumes less significant in the country, though, the seeds have great commercial value, which reinforces the importance of assessing seed physiological quality. Coriander (Coriandrum sativum L.) is a crop consumed in various regions of Brazil, especially in the North and Northeast. Vegetable widely consumed in Brazil as a condiment featuring great socio-economic importance. However, problems related to low seed vigor and crop establishment are reported in this specie [6]. There are only few studies about the use of vigor test to estimate the seeds physiological potential of

Physiological and Phytosanitary Potentials of Coriander and Radish Seeds

these species [2, 6, 7]. In this context, the objective of this study was to evaluate the seed physiological quality of lots of radish and coriander.

2. Materials and Methods 2.1 Materials The work was conducted at the Seed Analysis Laboratory and in the greenhouse of the Federal University of Pelotas. Seeds from four lots of radish seeds cultivar “Saxa” and from four lots of coriander seeds cultivar “Verdão” were subjected to following tests and assessments described below.

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mL plastic cups containing 50 mL of deionized water. The readings were taken at 2 h, 4 h, 6 h, 8 h and 24 h. The conductivity value provided by the device was expressed in mS cm-1 g-1. 2.6 Accelerated Aging with NaCl (Sodium chloride) Solution A total of 200 seeds (four replicates of 50 seeds) per seed lot were distributed over an aluminum screen placed inside a plastic box (gerbox) containing 40 mL of NaCl solution, maintained at 41 °C for 48 h. This solution was prepared by adding 40 g of NaCl in 100 mL of water, establishing an environment with relative

2.2 Determination of Moisture Content The experiment was conducted in an oven with forced air circulation at 105 ± 3 °C for 24 h, in accordance to the Rules for Seed Analysis RAS [8], using two samples of 4 g seed for each lot. Results were expressed as mean percentage weight per lot. The moisture content of the seed was assessed before and after the accelerated aging test.

humidity of 76%, according to the procedure proposed by ref. [9]. After this period, the seeds were put to germinate following the methodology used in the germination test described above. The percentage of normal seedlings was assessed on the fourth (radish) and seventh (coriander) days after sowing. 2.7 Seedling Emergence in Substrate The sowing of each lot was manual, in beds, in a

2.3 Germination Test The experiment was conducted at 20 °C with 200 seeds per seed lot (four replicates of 50 seeds). The seeds were distributed on two sheets of paper, previously moistened with distilled water in an amount equivalent to 2.5 times the mass of paper. Evaluations were conducted for radish at 4 and 10 days and for coriander at 7th day and 21th day after sowing and the results expressed in percentage of normal seedlings [8]. 2.4 First Count of Germination The experiment was made in conjunction with the germination test, by computing the percentage of normal seedlings on the fourth day after sowing for radish and seventh day for coriander [8]. 2.5 Electrical Conductivity The experiment was assessed with four replications of 50 seeds per seed lot. The seeds were soaked in 200

greenhouse, with four replicates of 100 seeds in rows 2.0 m long with spacing of 0.20 m at a depth of 0.01 m to coriander seeds. For the radish seeds were sown four replications of 50 seeds in furrows spaced at 0.20 m and 0.01 m depth. Evaluations were performed at 12 days after sowing for radish seeds and 30 days for coriander seeds, computing normal seedlings emerged and the results expressed as a percentage. 2.8 Statistics The data expressed in percentages were subjected to normality tests that indicated they did not need any transformation. The experimental design was completely randomized layout with five repetitions. In the statistical procedure, analysis of variance was performed separately for each test and the means of the lots were compared by Tukey test at 5% probability. The conductivity test was analyzed in a factorial of 4 lots  5 seed imbibition periods.

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3. Results and Discussion The water content of the seeds was similar between lots, which allow obtaining more consistent results. The germination rate of all radish seed lots used was above 95%, which is above the minimum standard required for commercialization of most seed vegetable crops (80%). These germination values indicate high physiological seed quality and seedling emergence in the greenhouse ranged from 80% to 88%, depending on the lot (Table 1). Radish seed lots did not differ on the percentage of germination (Table 1), showing low sensitivity of germination tests performed at the laboratory, to identify differences in performance of the seeds, often highlighted in the literature, justifying the use of vigor testing (Table 1). Using the laboratory germination test was also not possible to differentiate seed lots of lentil [10] and wheat [11], because the germination test is conducted under favorable conditions, maximizing the potential of physiological seed lots. However, the first count of germination test classified the seed lots into two different vigor levels (low and high). The data obtained by the author [12] in the first count of germination test in tomato seeds permitted the separation of the lots in two vigor levels, showing similar results as they were observed in this work (Table 1). The accelerated aging test with saturated solution of NaCl detected vigor differences between radish seeds lots, and a similar response was also observed in seedling emergence (Table 1). These results showed consistency with those obtained in the seedling emergence. The seed water content after aging period showed maximum change of 0.4% points among seed lots, not interfering, a priori in the results. Among the available tests, accelerated aging is one of the most studied and recommended for various crops. Initially developed for the purpose of estimating the longevity of stored seeds, it has been extensively studied with a view to its standardization [13] and its ability to provide information with high consistency

Table 1 Initial moisture content of the lots (IMC), moisture content after accelerated aging (MCA), percentages for germination test (G), first count of germination (FCG), accelerated aging with NaCl-76% (AA), emergence of seedlings in substrate (ESS) of the different lots of radish seeds. Lots IMC(%) MCA(%) G(%) FCG(%) AA(%) ESS(%) 1 8.8 10.7 95 a 88 b 83 ab 84 ab 2 8.9 10.9 95 a 87 b 86 a 88 a 3 8.6 10.5 97 a 93 a 81 b 80 b 4 8.3 10.7 96 a 94 a 83 ab 86 ab CV (%) 3.22 5.25 4.93 5.31 Means followed by the same letter in a column do not differ in level of 5% probability by the Tukey test.

degree [1]. This method was also efficient for evaluating seed vigor of different vegetable seeds such as carrot [13], cucumber [14], tomato [15], melon [16] and rocket [17]. For the electrical conductivity (Table 2), it was found that there was no significant interaction between the periods of soaking and lots of radish seeds, although this test detected differences in vigor levels into four lots, with superiority for lots 1 and 2 and inferiority for lot 3. With increasing imbibition time was greater leaching of exudates from seeds. However, for black oat seeds, the electrical conductivity test at the different conditions detected difference based on seed vigor levels. Furthermore, there were significant effects only on main factors: lots of seeds, number of seeds and imbibing periods [17]. Among vegetable seeds, coriander has a national standard germination of (60%) and it is considered low for seed commercialization. Lots tested in this present work, seed lot germination exceeding the minimum value and there was a variation between lots from 71% to 81% (Table 3). In the germination test was observed that lot 2 showed lower seed germination than other seed Lots (Table 3). This result as also reported [18], they found that the germination test was not sensitive enough to distinguish differences physiological quality of onion seed lots, being only able to show the inferiority of one of the tested lots.

Physiological and Phytosanitary Potentials of Coriander and Radish Seeds Table 2 Electrical conductivity test with soaking 50 seeds in 50 mL of distilled water for periods of 2, 4, 6, 8 and 24 h from four radish seed lots. Periods of imbibing (h) 2 4 6 8 24 Média 1 32.90 42.30 46.80 51.40 62.40 47.44 B 2 32.00 41.00 43.70 47.60 58.70 44.60 A 3 36.80 46.10 51.60 57.40 65.40 51.46 C 4 34.50 43.60 47.20 52.10 64.80 48.44 B Média 34.05 a 43.23 b 47.32 c 52.12 d 62.82 e CV (%) 9.00 Means followed by same letter in lower case in the line and capital letters on the column do not differ by Tukey test at 5% probability. Lots

Table 3 Initial moisture content of the lots (IMC), moisture content after accelerated aging (MCA), percentages for germination test (G), first count of germination (FCG), accelerated aging with NaCl-76% (AA), emergence of seedlings in substrate (ESS) of the different lots of coriander seeds. Lots IMC(%) MCA(%) G(%) FCG(%) AA(%) ESS(%) 1 8.8 10.7 81 a 72 a 35 a 50 b 2 9.1 11.9 71 b 63 bc 15 c 35 c 3 8.8 10.7 82 a 59 c 26 b 53 b 4 8.9 11.7 77 a 66 b 35 a 61 a CV(%) 7.74 8.26 10.0 10.3 Means followed by the same letter in a column do not differ in level of 5% probability by the Tukey test. Table 4 Electrical conductivity test with soaking 50 seeds in 50 ml of distilled water for periods of 2, 4, 6, 8 and 24 h from four coriander seed lots. Lots 1 2 3 4 Average CV(%)

Periods of imbibing (h) 2 4 6 8 330 362 388 398 476 512 521 535 317 342 358 365 556 600 625 635 420 a 454 b 473 c 483 c 6.04

24 468 615 432 724 560 d

Average 389 B 532 C 363 A 628 D 478

The first count germination test separated the seed lots in different vigor classes: high vigor (lot 1), low vigor (lot 3), and intermediate vigor (lots 2 and 4). Results similar to those obtained in the present study were reported [19], working with corn, found that test first countal lowed to classify lots into three vigor levels (high, low and intermediate).

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The accelerated aging test, performed for 48 h at 41 °C was excessively drastic because of reducing seed germination by more than 50% points in relation to non-aging seeds; this situation can compromise the test result. However, this test found differences between seed lots and allowed to separate the three seed lots into vigor levels (Table 3). Similar results were obtained [20], with cotton seed, because in less severe aging conditions, 41 °C for 48 h, most of the seed lots had germination decreased by about 50% points compared to initial values. Despite drastic effects, aging at 41 °C for 48 hallowed to classify lots into four and three vigor levels. For all lots, in general, seedling emergence was low, ranging from 35% to 61%. The physiological seed quality is routinely assessed by laboratory germination test; however, it is believed that this test conducted under appropriate conditions can super estimate the seed vigor [21]. In this case, if the ambient conditions after sowing are not optimal, the percentage of seedling emergence may be less than determined in laboratory [22]; and this occurrence was found in this work. Seedling emergence separated the seed lots into three vigor levels, highlighting lot 4 as greater vigor, lot 2 as a lower physiological potential and the other as intermediaries. The worst performance presented by the seeds of lot 2 in the test seedling emergence was also observed in germination and accelerated aging. In the electrical conductivity test there was a significant effect on the interaction seed and imbibing periods (Table 4). However, it was possible to stratify the lots based on the vigor. Lot 3 showed higher vigor and lower lot 4, contradicting the vigor levels separation obtained in accelerated aging tests and seedling emergence. The first count test, accelerated aging and seedling emergence showed efficient differentiation of physiological quality of seed lots of coriander, however, the tests do not separated lots exactly the same way. The accelerated aging test despite being

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very dramatic was allowed to rank the lots a manner similar to the results observed in seedling emergence.

[8]

4. Conclusions The accelerated aging test using saturated saline solution showed efficiency in assessing the physiological quality of both lots of radish seeds and coriander. This test at 41 °C for 48 h is recommended to be used for both species.

[9]

[10] [11]

Acknowledgments [12]

The authors would like to thank the supporting agency, CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior), for granting a scholarship

[13]

to the first author and CNPq (ConselhoNacional de Desenvolvimento Científico e Tecnológico) for financial support that was indispensable for the

[14]

accomplishment of this work.

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