Abnormal Seedlings Research Articles

English

This study evaluated the presence of integument dormancy in Melanoxylon brauna seeds by testing the influence of nine pre-germination treatments on seed germination compared to a control (no pre-germination) treatment. Pre-germination treatments include; immersion in sulfuric acid for 5 min, 10 min, 15 min and 30 min, hot water at 80°C without soaking, hot water at 80°C with soaking for 30 min, 90 min, 24 h, and mechanical scarification. The experiment consisted of a completely randomized design, with four replicates and 25 seeds per experimental unit. Percentage germination, germination speed, number of normal and abnormal seedlings, and mortality rate were evaluated. Seeds began to germinate at four days, and germination varied from 33 to 89%, with the highest percentage found in hot water with or without soaking for 30 min, which not differed statiscally from control. Immersion in sulfuric acid for longer than 10 min reduced seed germination and increased mortality rate. We conclude that M. brauna seeds do not undergo seed dormancy, and there is no need to apply pre-germinating treatments to its seeds. Key words: Dormancy, seed technology, Leguminosae.

Online Ring Testing to Elicit the Cause of Underdispersion in Seed Germination Tests

According to International Rules for Seed Testing, a germination test is performed with 400 seeds, subdivided into four replicates of 100 seeds. The empirical variance between the four replicate results was found by many authors to be smaller than random sampling variation. Hypotheses for sources for this underdispersion were developed, but no experimental proof was possible, as the population's true germination value is unknown. To overcome this obstacle, we performed two online ring tests with computer‐generated seedling images. Seedlings had to be classified as normal, if the shoot/root ratio was between 0.5 and 2.0, otherwise as abnormal. Results showed significantly smaller variances between empirical replicate results than between true replicate values, confirming underdispersion. Rates of false normal and false abnormal classification of seedlings were 19.5 and 3.5%, respectively. Error rates are different between analysts and depend on the true replicate value. In replicates with many abnormal seedlings, the false normal rate is higher and the false abnormal rate is lower than in samples with few abnormal seedlings. This is the source of underdispersion and a direct result of decisions made by seed analysts. Pooling of replicate results of all analysts and recombining showed that underdispersion can be reduced significantly when each replicate is tested by a different analyst. Hence, replicates should be blinded and every replicate evaluated by another analyst.

Evaluation of important seed and sprout traits as potential selection criteria in breeding varieties for sprout soybeans

Soybean sprouts, a traditional vegetable in Asia, are gaining popularity in the United States. Soybean sprout demand has been supplied by natto (a Japanese soyfood) cultivars that share some seed characteristics with sprout cultivars. However, natto seeds do not meet all requirements of sprouts and are rejected by sprout manufacturers. The objectives of this study were to evaluate important seed and sprout traits as potential selection criteria in breeding sprout soybeans and to study the storage effect on soybean sprout quality. Almost all genotypes produced thicker and longer hypocotyls and higher fresh-sprouts than ‘MFS-561’, a commercial soybean sprout variety. Hypocotyl length ranged from 13.8 to 16.2 cm. Four fungi genera Bipolaris sp., Cercospora sp., Botrytis sp. and Caethomium sp. were isolated from seeds. Cracked cotyledons and abnormal seedlings were the two main constraints affecting soybean sprout quality. Correlation coefficients among all traits indicated that percentage and weight of high- and average-quality sprouts would determine sprout yield. Acceptable yield and several traits were recommended to be used simultaneously while breeding superior sprout soybean cultivars. Good sprout varieties should produce high-quality sprouts >48%, average-quality sprouts 5.7 g/g seed, hypocotyl thickness >1.6 cm and hypocotyl length >13 cm. One-year seed storage at room temperature reduced sprout quality. V09-3876 and V12-1939 had superior seed and sprout traits and are promising lines for further evaluation for sprout production. Seed storage over time affects seed germination and seedling vigor, and fungi on seed can cause reduced seed quality.

Seed Treatments to Improve Field Emergence of Soybean Seed.

This study was conducted at Seed Technology Research Unit in Mansoura, Seed Technology Research Department and Tag El-Eiz Experiment Station, ARC, Egypt during 2014 and 2015 yearsto improve seed quality and field emergence of soybean (c.v Giza 111) lots (new and old) through some seed treatment methods i.e.magnetic field(0, 30, 60 and 90 mT), seed priming in ascorbic acid (0, 50, 100 and 150 ppm) and magnetic-priming (magnetic field + seed priming). The main results could be summarized as follows that expose soybean seed to magnetic field up to 90 mT increased seed vigor (normal seedling, germination rate and field emergence), seedling vigor (shoot and radical lengths and seedlings dry weight), enzyme activity (ascorbateperoxidase and catalase) and reversed abnormal seedling andungerminated seed. Seed priming with ascorbic acid significantly increased all studied traits, except abnormal seedlings and radical length. Seed priming in ascorbic acid (150ppm) recorded the highest means of germination % under laboratory and field emergence, shoot length and catalase activity comparing dry seed. Treating soybean seed by magnetic-priming method significantly affected all studied traits. Magnetic-priming treatments (60mT+150ppm ascorbic acid) and (90mT+150ppmascorbic acid) recorded the highest means of seed germination, seedling vigor and field emergence for new and old seed respectively. Generally, it could be improve of seed quality under laboratory and field emergence of soybean (c.v Giza 111) of old seed(one year stored) and get germination % under laboratory and field conditions above the level of acceptance certified seed (75%) by treating seed with magnetic-priming treatment (magnetic field 90mT+ priming inascorbic acidat the rate of 150ppm).

Determination of the optimal condition for ethylmethane sulfonate-mediated mutagenesis in a Korean commercial rice, Japonica cv. Dongjin

Ethylmethane sulfonate (EMS) mutagenesis is a powerful hunting tool to seek novel players for improving agromonic traits. Together with rapid evolution of the next-generation sequencing techniques, the EMS mutagenesis has been revaluated for its utilization to breed crops in practical agriculture and to study functions of key players in valuable agronomic traits. In this study, we systematically investigated conditions for EMS mutagenesis in Dongjin (Oryza sativa, Japonica) rice plants to make a mutant population. Since the EMS mutagenesis depends on target tissue, EMS concentration and EMS exposure time, we fixed the EMS exposure time as 13 h and treated germinating seeds with various levels of EMS dosage (from 0.25 to 2% EMS concentration). EMS treatment clearly showed negative biological influences including low germination and abnormal seedling development of Dongjin rice plants. Based on the standard of about 50% lethal dose, 0.75 and 1% EMS dosage for 13 h was finally selected as the optimal conditions for EMS mutagenesis of Dongjin germinating seeds.

EXTRATOS DE Brunfelsia uniflora NA GERMINAÇÃO DE SEMENTES DE Crotalaria spectabilis

As sementes do gênero Crotalaria L., de um modo geral, apresentam dificuldades no processo germinativo. O objetivo da pesquisa foi avaliar a eficiência do extrato bruto de Brunfelsia uniflora na germinação de Crotalaria spectabilis. O delineamento foi inteiramente casualizado, com quatro tratamentos e quatro repetições. Os tratamentos foram extratos das folhas e flores de B. uniflora nas concentrações 25, 50, 100% e tratamento testemunha (0%). O experimento foi conduzido no laboratório de Fitopatologia da Universidade Paranaense – UNIPAR, Umuarama - PR. As folhas e frutos coletados foram expostos à secagem natural e posteriormente submetidos ao processo de maceração dinâmica com esgotamento e rota evaporação do etanol, obtendo o extrato bruto. As sementes foram expostas as diluições do extratos durante dois minutos, na sequência, foram dispostas para a secagem e distribuídas em rolo papel e armazenados na B.O.D., na temperatura de 26ºC. Na contagem, aos 4 e 10 dias, determinou-se a porcentagem de plântulas normais e anormais, sementes duras e dormentes. Os extratos brutos da folha e flor de B. uniflora não ocasionaram diferenças estatísticas significativas para as variáveis analisadas, demonstrando ausência de efeito antagônico.

Developing eco-friendly biofungicide for the management of major seed borne diseases of rice and assessing their physical stability and storage life

Three plant oils (Cymbopogon citratus, Cymbopogon martini, and Pelargonium graveolens) were developed as EC formulations and tested for their physical stabilities. EC formulations (10EC, 20EC and 30EC) of C. citratus, C. martini and P. graveolens had emulsion stability, spontaneity property, heat and cold stability. EC formulated plant oils were screened against the major seed borne fungi of rice such as Curvularia lunata, Fusarium moniliforme, Bipolaris oryzae, and Sarocladium oryzae. The level of inhibition varied among the concentrations of EC formulations. Among the three EC formulations, that of C. citratus oil 30EC recorded 100% inhibition on the mycelial growth of test pathogens. In the blotter paper method, rice seeds treated with a formulation of C. citratus oil 30EC controlled the infection of C. lunata, F. moniliforme, B. oryzae and S. oryzae in rice seed to the tune of 66.0%, 60.4%, 66.0% and 69.1%, respectively. Seed soaking with formulation of C. citratus oil 30EC showed the highest percentage of normal seedlings, the lowest number of abnormal seedling and fresh ungerminated seeds when tested with the roll-towel method. Seed soaking with 30EC formulation of C. citratus oil increased seed germination, shoot length, root length and vigour of rice seedlings when tested with the plastic tray method. Transmission of pathogens from seed to seedling was reduced significantly by the 30EC formulation of C. citratus oil when tested with the plastic pot method. The effect of the storage life of the 30EC formulation of C. citratus oil showed that it had retained their antifungal effect till the end of the incubation period (120 days), and is able to inhibit the mycelial growth of all test pathogens to the 100% level.

Comportamento de híbridos de canola e suas gerações F2: qualidade fisiológica e sanitária de sementes

The objective of this study was to compare the physiological and sanitary quality of canola hybrids and their respective F2 generations. The F2 generation seeds of commercial canola hybrids Hyola 61 and Hyola 433, harvested in July 2014, were evaluated as well as the hybrid seeds. The factorial arrangement (2x2) (Hybrid x Generation) in a completely randomized design was used, with four replications. The germination tests were carried out, tetrazolium, electrical conductivity and seed health, based on the percentage of contaminated seeds. The obtained seedlings had both shoot and root system length measured. The sanitary quality was assessed based on the percentage of seeds contaminated with Aspergillus spp. and Colletotrichum spp. fungi. There was a significant interaction between F2 generations and hybrids for the first count characteristics (PCG), second germination count (SCG) and shoot length (CPA). On the physiological quality, reduction in germination occurred only for hybrid Hyola 61, having approximately 43% less than the hybrid seeds germinated for the F2 generation. There were also differences between generations of abnormal seedlings characteristics and electrical conductivity, and the F1 progeny showed higher values for both. With regards to health quality, Aspergillus spp. and Colletotrichum spp. fungi. were checked, but there was no difference in the the F1 and F2 seeds and neither for hybrids. In the present study, there was differential behavior to the variable seed germination between the F1 and F2 generations; unlike the health quality was not reduced, showing no difference between hybrids and generations.

Genetic diversity in soybean seed quality under different storage conditions

This study aimed to assess the effect of genetic diversity on physiological quality of soybean seeds stored in cold chamber and under environmental conditions. Ten cultivars were assessed in a randomized factorial design (2x10). Factor 1 corresponded to two storage conditions and factor 2 to ten soybean cultivars, with four replications. The evaluated variables were total germination (G%), first count of germination (F%), percentage of abnormal seedlings (AS%), germination speed index (GSI), water content (WC), electrical conductivity (EC), dry matter of seedlings (DMS) and length of seedlings (LS). Data underwent ANOVA, followed by Scott Knott test, as well as multivariate analysis of genetic diversity. The results showed a higher physiological quality for seeds under cold storage. Half of the cultivars (FPS Júpiter, FPS Urano, FPS Antares, FPS Netuno and CD 250) presented high germination rates and seed vigor, being thus indicated as high-standard materials for further breeding programs. Besides that, storage environment had influence on the clustering of soybean cultivars. Moreover, cultivars had genetic dissimilarity for almost all assessed traits as G%, GSI, F%, AS%, EC, DMS and LS.

Isolated and Community Contexts Produce Distinct Responses by Host Plants to the Presence of Ant-Aphid Interaction: Plant Productivity and Seed Viability.

Ant-aphid interactions may affect host plants in several ways, however, most studies measure only the amount of fruit and seed produced, and do not test seed viability. Therefore, the aim of this study was to assess the effects of the presence of ant-aphid interactions upon host plant productivity and seed viability in two different contexts: isolated and within an arthropod community. For this purpose we tested the hypothesis that in both isolated and community contexts, the presence of an ant-aphid interaction will have a positive effect on fruit and seed production, seed biomass and rate of seed germination, and a negative effect on abnormal seedling rates, in comparison to plants without ants. We performed a field mesocosm experiment containing five treatments: Ant-aphid, Aphid, Community, Ant-free community and Control. We counted fruits and seeds produced by each treatment, and conducted experiments for seed biomass and germinability. We found that in the community context the presence of an ant-aphid interaction negatively affected fruit and seed production. We think this may be because aphid attendance by tending-ants promotes aphid damage to the host plant, but without an affect on seed weight and viability. On the other hand, when isolated, the presence of an ant-aphid interaction positively affected fruit and seed production. These positive effects are related to the cleaning services offered to aphids by tending-ants, which prevent the development of saprophytic fungi on the surface of leaves, which would cause a decrease in photosynthetic rates. Our study is important because we evaluated some parameters of plant fitness that have not been addressed very well by other studies involving the effects of ant-aphid interactions mainly on plants with short life cycles. Lastly, our context dependent approach sheds new light on how ecological interactions can vary among different methods of crop management.

English

The standard germination tests have been commonly used on commercial grain crops, such as soybean, field beans, rice and maize. However, there are no standard tests for potential new crops; quinoa being one of them. This work is aimed at evaluating the effect of substrate, temperature and counting time in seed germination of quinoa. The following treatments were used in tests with seeds: on blotter paper, between blotter paper, on sand and within sand, all previously soaked with distilled water. These substrates were combined to the temperatures of 15, 20, 25, 30°C, and alternated between 20 to 30°C. The experiment was conducted on an entirely randomized factorial design 5 × 4 (temperature × substrate) with 4 repetitions. Normal seedlings, abnormal seedlings and dead seeds were counted until stabilized. The germination velocity index and mean time for germination were calculated.  From the results, it was concluded that germination test of quinoa seeds should be conducted at 20 to 30°C alternate temperatures, on or between blotter paper, with initial count at 2 days and final count at 4 days. Key words: Chenopodium quinoa willd., substrate temperature, counting time, seed viability.

Research Article Physiological Traits and Their Relationships in Black Oat Populations

The objective of this work was to verify physiological quality of black oat populations, in order to know and point out the relationships among physiological characters for selection of progenies. The experiment was carried out at the Laboratory of Plant Breeding and Production, Federal University of Santa Maria, Campus of Frederico Westphalen - RS. Seed samples were collected from 14 black oat populations from small producers in the region, and cultivars BRS Madrugada and BRS Centauro (populations 15 and 16, respectively). A randomized block design with four replications was used. It was evaluated seed length, seed width, thousand seed weight, percentage of germination, non-germinated seeds, abnormal seedlings, hypocotyl length, root length, dry matter of seedlings. Populations revealed a difference in the physiological quality of seeds, and populations 1, 8, 9, 11, 12, 13, with germination within the required standard, have a greater potential to compose progenies. Seed width, thousand seed weight, dry matter of seedlings and hypocotyl length revealed association with germination. It is worth highlighting that seed width and thousand seed weight are characters of easy and immediate measurement that can guarantee greater efficiency of selection.

<b>Responses of quinoa (<i>Chenopodium quinoa</i> Willd.) seeds stored under different germination temperatures

In this experiment, we assessed the germination and vigor of quinoa seeds packed in paper bags and stored at room temperature for 36, 85, 119, 146, 177 and 270 days. The seeds were harvested under experimental conditions in Marechal Candido Rondon, Paraná, during the 2012/13 growing seasons. Four replicates of 100 seeds each were established for each storage time, and the seeds were evaluated, on paper, based on the BOD under the following experimental temperature conditions: alternating temperatures of 20 and 30°C and a constant temperature of 25°C. The seeds from both treatments were subject to seven-hour photoperiods and 25°C under continuous darkness. The germinated seeds were counted daily for eight days after sowing, and we evaluated the percentages of normal and abnormal seedlings and the germination index. The experimental design was completely randomized using a split-plot design. Increasing the storage time decreased the percentage of germinated seeds and seed vigor due to the increased number of abnormal seedlings. Over the 430-day study period, quinoa seed germination completely declined under the experimental conditions. The final number of germinating seeds should be evaluated 7 days after the beginning of the germination test.

RESPOSTA FISIOLÓGICA DE SEMENTES DE PARICÁ SUBMETIDAS A ESTRESSE SALINO

Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby known as parica, is a tree species in the Amazon region with potential for planting in degraded areas, reforestation and agroforestry systems. This study aimed to evaluate the physiological behavior of parica seeds in relation to salt stress by potassium chloride (KCl) and sodium chloride (NaCl), diluted in distilled water with different concentrations (0, 25, 50, 75 and 100 mM). The experimental design was entirely randomized, with five treatments and four replicates of 25 seeds each. The germination percentage, average time of germination, first count of germination, normal seedlings and abnormal seedlings, were evaluated. Data were submitted to analysis of variance and regression, using the equation that best fit the data. Under salinity stress conditions these seeds were able to germinate, but, the salinity significantly reduced the percentage of germination, first count and the amount of normal seedlings and determined the increase in the average time of germination and abnormal seedlings, causing deformations, irregularities and significant reductions in the growth of seedlings, which means that for this culture there is a certain tolerance to salt stress and these results provide information to guide future plantations about the most suitable areas to their establishment

Effect of different sowing dates on Azivash (Corchorusolitorius) seed quality

This study was conducted at the Gorgan University of Agricultural Sciences and Natural Resources farm, Iran, Golestan province with about 600 mm annual rainfall in order to evaluate the effect of different sowing dates on Azivash (Corchorusolitorius) seed quality, using a randomized complete block design with three replications on 2013. Treatments were four sowing dates such as May 5, Jun 5, Jul 11 and Agu 6. After seed maturity and harvesting, a seedling growth tests were done for each sowing date treatment in four replications. It used 25 number seeds in each replication. Seedling growth test was performed by BP (between paper) method for 7 days at 25C in incubator. The results showed that effect of sowing date treatment was significant on normal seedling percentage, abnormal seedling percentage, non-geminated seeds percentage and radicle and hypocotyl length. Mean comparison results showed that maximum normal seedling was recorded in Jun 5, Jul 11 and Agu 6 sowing dates. Minimum non-germinated seeds were recorded in Jul 11 sowing date. Also, seeds of Jul 11 sowing date treatment had the highest hypocotyl and radicle length. With regard to these founding and positive correlation between radicle length and normal seedling percentage and hypocotyl and radicle length with abnormal seedling percentage Jul 11 sowing date is the best sowing date for Azivash (Wild okra) cultivation in Gorganregional at Golestan province because of production of highest normal seedling production, lowest non-germinated seeds and longer hypocotyl and radicle length that result to highest seed quality and vigor.

Effect of Synthetic Auxin Herbicides on Seed Development and Viability in Genetically Engineered Glyphosate-Resistant Alfalfa

Feral populations of cultivated crops have the potential to function as bridges and reservoirs that contribute to the unwanted movement of novel genetically engineered (GE) traits. Recognizing that feral alfalfa has the potential to lower genetic purity in alfalfa seed production fields when it is growing in the vicinity of foraging pollinators in alfalfa seed fields, industry has established production standards to control feral plants. However, with the commercialization of GE glyphosate-resistant (GR) alfalfa and the need to support the coexistence of both GE and conventional production, effective methods to control transgenic feral alfalfa need to be developed. Therefore, a study was conducted in 2012, 2013, and 2014 to determine the effect of several synthetic auxin herbicides on seed development in GR alfalfa. GR alfalfa, var. Genuity (R44BD16), was treated with dicamba, 2,4-D, triclopyr, and aminopyralid when alfalfa plants contained green seed pods. Two weeks after herbicide application, plants were harvested, air dried, and seed yield, seed germination, and seedling emergence from the soil were determined. In 2013, dicamba, triclopyr, and 2,4-D decreased alfalfa seed yield per plant compared wih nontreated plants, whereas in 2014, all four herbicides decreased alfalfa seed yield per plant 24 to 49% (by weight) compared with nontreated plants. The same trend was evident in 2012, but seed yield was variable and was not significantly different among treatments. Seed germination averaged 43, 50, and 72% in 2012, 2013, and 2014, respectively, and was not affected by the four herbicides applied at early pod-fill stage. However, seeds harvested from plants treated with dicamba, 2,4-D, and triclopyr often produced deformed and abnormal seedlings, and when planted in soil, frequently failed to emerge. The combined effects of dicamba, 2,4-D, and triclopyr in reducing seed yield, seedling emergence, and seedling growth could contribute to managing feral alfalfa populations.

English

Seeds of watermelon [Citrullus lanatus (Thunb.) Matsum and Nakai, cv. Crimson Sweet] were used to investigate the effects of different priming techniques on seed germination and early seedling growth. The seeds were soaked in solutions of 0.2% gibberellin (50 mg L–1 gibberellic acid), 0.2% cytokinin (90 mg L–1 kinetin), 0.2% potassium nitrate (2 g L–1 KNO3), 0.2% calcium nitrate [2 g L–1 Ca(NO3)2] or water (hydropriming) for 6 h at 25°C. After drying, five replicates of 25 seeds were distributed in plastic boxes with blotter paper and kept into a seed germinator at 26°C for 12 days. The different priming treatments significantly affect the measurements of the seed germination and growth of watermelon seedlings. The germination of watermelon seeds ranged from 0 to 100%, and was significantly greater when seeds were subjected to priming with GA3, KNO3, Ca(NO3)2 and water (control), and lower under cytokinin (CK) priming. The seed priming with 0.2% solution of CK resulted in 100% of abnormal seedlings, and therefore should not be used by watermelon growers. Seed priming with GA3, KNO3, Ca(NO3)2 and water (hydropriming) increased the shoot length, whereas GA3, Ca(NO3)2 and water priming improved the radicle length, as well as shoot dry matter watermelon seedlings. The KNO3 and water priming increased the root dry matter of watermelon seedlings. Seed priming with KNO3 and Ca(NO3)2 improved the germination rate and seedling vigor index. The results of this study show that seed priming with GA3, KNO3, Ca(NO3)2 and water (hydropriming) may be useful tools due to their positive effects on germination percentage and growth characteristics of watermelon seedlings. Key words: Citrullus lanatus, cytokinin, gibberellin, hydropriming.

Methods for overcoming dormancy in Stryphnodendron pulcherrimum seeds

Seed dormancy is a phenomenon observed in several tropical species. This condition causes low and non-uniform germination. The present study was designed to identify an efficient method of breaking seed dormancy in Stryphnodendron pulcherrimum. Seeds of four mother plants were subjected to the following treatments: immersion in sulfuric acid for 2, 4, 6, 8, 10 and 12 min and scarification on 150-grit sandpaper. Seeds were sown on substrate containing sand and sawdust (1:1). It was evaluate the days to onset seedlings emergence, seedlings emergence (SE), emergence speed index (ESI), germination (G), hard seeds (HS), dead seeds (DS), dormant seeds (DMS), abnormal seedlings (AS) and dry mass of aerial part (DMAP) and roots (DMR). The experimental design was completely randomized with four replications of 25 seeds for each treatment. Data were subjected to analysis of variance and means compared by Tukey's test (p < 0.05). Significant differences among treatments were observed for ESI, SE, G, HS, DMAP and DMR. Highest HS was observed in control treatment (85%). Highest G was observed in seeds scarified with sulfuric acid for 10 min (82%) and 12 min (74%). These treatments also showed highest ESI, DMAP and DMR, indicating that these scarification treatments were the most efficient in overcoming dormancy.

Viabilidad y germinación de semillas de Hechtia perotensis (Bromeliaceae)

Endemic populations of Hechtia perotensis have been described in Puebla and Veracruz, Mexico. Good quality seed collections can be used in conservation, research and ecological restoration. To evaluate seed quality of wild and endemic species, some compounds are used as effective promoters of germination, such as potassium nitrate (KNO3) and gibberellic acid (AG3), because they increase seed germination capacity and reduce latency. The triphenyl tetrazolium chloride (tetrazolium) test correlates seed viability because it is based on the activity of dehydrogenases in live tissues that catalyze mitochondrial respiration. The objective of this study was to obtain information on size and weight of capsules and seeds and seed germination and viability of H. perotensis, collected in Veracruz in the year 2012 and 2015. The hypotheses were 1) that seed germination and viability are independent of the year of collection, 2) that there is a tetrazolium concentration that can identify seed viability better than others, and 3) that pretreatment with KNO3 or AG3 improves seed germination. Seed germination was assessed using a completely randomized design with three treatments (control and the germination promoters 0.2 % KNO3 and 500 mg/L AG3), four treatments for the viability test (control, 0.2, 0.5 and 1.0 % of tetrazolium) and six replicates for each treatment. A total of one hundred seeds for germination experiments, and 25 seeds for the viability test were used. The results between and within years were analyzed with ANOVA and multiple comparison with the Tukey test. The proportion of non-germinated seeds was quantified along with the number of normal and abnormal seedlings, seeds with viable embryo, seeds without embryo, and seeds with low or no viability. On average, for the 2012 collected sample, 36 % had viable embryos, 7 % had low viability, 24 % were not viable and 33 % had no embryo. This result was significantly different from the 2015 sample, for which 87 % of seed showed viable embryos, 10 % had low viability, 0 % was not viable and 3 % had no embryo. Seed germination was also significantly different between years (22 and 92 %) Pregerminative treatments did not improve germination. Seed germination and viability of H. perotensis significantly varied between years of seed collection.

Efeito de stresse salino em sementes de Phaseolus vulgaris

Saline soils tend to impair germination and plant growth of various crops, resulting in agroeconomic problems. This study aimed to verify the physiological performance of common bean seeds submitted to salt stress. The research was conducted in the Plant Physiology Laboratory, Department of Biology and Animal Science, UNESP, Ilha Solteira, SP, Brazil, in May 2014, using common bean cv. Perola seeds. The design was completely randomized, with six treatments (0; 1,309; 1,964; 2,620; 3,273 and 3,928 g NaCl L-1) and four replications. The observations were recorded for: % germination, number of abnormal seedlings, root and shoot length, fresh and dry weight of the roots, shoots and cotyledons, electrical conductivity and accelerated aging. The different levels of saline tested did not affect the germination parameters, number of abnormal seedlings and electrical conductivity. Consequently, for these parameters, the seeds of the cultivar Perola had good physiological performance. The root and shoot length parameters, were sensitive to higher salinity levels.