Abnormal Seedlings Research Articles

팥 포장출현력 예측을 위한 종자세 검사

경실로 인해 다른 두과작물에 비해 포장 입묘가 불량한 팥의 포장출현율의 효과적인 예측 방법을 개발하기 위해 인위로 노화 정도를 조절한 종자에 대해 실험실에서 몇 가지 종자세 검사를 실시하여 포장출현력과 비교하였다. 얻어진 종자세 지표들에 대해 포장출현력과의 상관분석을 통해 예측을 위한 효율적인 지표들을 도출하였다. 팥에서 종자세가 높을 경우에는 표준발아검사에서의 종자활력률이 포장출현력 예측에 효과적이며, 약간 노화된 종자의 경우에는 저온발아검사(CGT)에서의 비정상묘율과 배축의 길이는 포장출현력과 높은 상관관계를 보였으며, 전기전도도와 CSVT에서의 활력률과 테트라졸리움 검사에서 종자세와 예측발아율은 포장출현력과 5% 수준에서 상관관계가 인정되었다. 종자세가 낮은 종자에서는 CSVT에서 불발아종자율이 포장출현력과 5% 수준에서 상관을 보였다. 포장출현력 예측에 효과적인 몇 가지 종자세지수를 이용하여 stepwise multiple regression 분석을 실시한 결과 테트라졸리움(TZ) 검사에서의 예측발아율은 결정계수(<TEX>$R^2$</TEX>)가 0.820으로 포장출현력 예측에 가장 효과적인 검사방법임을 알 수 있었다. 표준발아검사(SGT)에서의 종자활력률, 저온발아검사(CGT)에서의 정상묘율과 건물중을 회귀방정식에 추가함에 따라 86.9% 까지 포장출현력 예측효율을 증가시킬 수 있었다. Field emergence of Azuki bean is poor due to hard seed coat as compared to other legumes. In this study, an attempt was made to develop prediction method with regression analysis based on various seed vigor tests in laboratory for field emergence of azuki bean. Azuki bean seeds artificially aged to provide various levels of seed quality were evaluated by the standard germination test (SGT), cold germination test (CT), cool germination test (CGT), complex stressing vigor test (CSVT), tetrazolium(TZ) vigor test and electroconductivity test. The SGT was suitable for predicting the field emergence in the unaged high vigor seeds. The abnormal seedling percentage and shoot length in the CGT were highly correlated with field emergence of moderate vigor seeds artificially aged for 2 days. Electroconductivity, seed viability in the CSVT, and vigor and predicted germinability in the tetrazolium vigor test were also useful for predicting field emergence. Percent of ungerminated seed in the CSVT was correlated with field emergence in the low vigor seeds artificially aged for 4 days. In a stepwise multiple regression analysis, seed viability in the SGT, normal seedling percentage and dry matter weight in the CGT accounted for 86.9% of the predicted value of field emergence in azuki bean.

The Effect of Weed Competition on Germination Indices and Seed Vigor of Chickpea

ABSTRACT- This experiment was carried out during the growing seasons of 2010 and 2011 at the Agricultural Research Farm of Bu-Ali Sina University, to study the effect of weed competition on subsequent germination and seed vigour of chickpea. 12 weed interference durations were evaluated in a randomized complete block design with three replications. Experiments consisted of two sets of treatments. In the first set, the crop was kept weed-free until 0, 14, 28, 42, 56 and 70 days after sowing and in the second set, weeds were permitted to grow within the crop until 0, 14, 28, 42, 56 and 70 days after sowing. Results of the two year experiments showed that the traits germination index, germination rate, mean germination time, percentage of germination, abnormal seedling percentage and seedling dry weight were affected by different duration of weed interference. Thereafter, the maximum value of germination rate and the minimum value of mean germination time belonged to the full weed-free condition. The increasing length of weed competition decreased seedling dry weight and increased abnormal seedling percentage. This finding is supported by a reduction in the seed weight. In other words, a decrease in seed storage contents resulted in a decrease in seedling growth and an increase in the percentage of abnormal seedlings.

Effects of different fungi on symbiotic seed germination of two Dendrobium species

The epiphytic orchid, Dendrobium aphyllum and D. devonianum are used as traditional Chinese medicine, and became locally endangered in recent years because of over-collection. We test the effect of inoculations of endophytic fungi FDaI7 (Tulasnella sp.), FDd1 (Epulorhiza sp. ) and FCb4 (Epulorhiza sp.), which isolated from D. aphyllum, D. denonianum and Cymbidium mannii, respectively, on artificial substrate in these two Dendrobium species. In the symbiotic germination experiment, FDaI7 and FDd1 were effective for protocorm formation and seedling development of D. aphyllum and D. denonianum separately. After 60 days, 14.46% of the D. aphyllum seeds grown to protocorms and 12.07% developed to seedlings inoculated only with FDaI7, while contrasted with 0 when inoculated the other two isolates and non-inoculation treatment. However, in D. denonianum, seeds only grown to protocorms and developed to seedlings when inoculated with FDd1, the percentages were 44.36% and 42.91% distinguishingly. High specificity was shown in symbiotic germination on artificial substrate of Dendrobium. Protocorms could further develop to seedlings within or without light when inoculated the compatible fungi. However, light condition (12/12 h Light/Dark) produced the normal seedlings, while dark condition (0/24 h L/D) produced the abnormal seedlings. These may suggest that the development of young seedlings require light based on the effective symbiotic fungi. These findings will aid in seedling production of simulation-forestry ecology cultivation, conservation and reintroduction of Dendrobium.

Seed Quality of Stored Soybean (&lt;i&gt;Glycine max&lt;/i&gt; L.) as Influenced by Storage Containers and Storage Periods

An experiment was conducted at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during April 2013 to June 2013 to study the effect of three storage containers (tin container, polythene bag and cloth bag); and five storage periods (0, 15, 30, 45, and 60 days) on the seed quality of soybean. The experiment was laid out in Completely Randomized Design (CRD) with four replications. The soybean seeds stored in tin container showed maximum germination capacity with high germination index, highest seedling growth, seedling dry weight per plant and vigour index. The seeds stored in cloth bag had the lowest seed quality during the testing period. The highest 1000-seed weight, moisture content, electrical conductivity, abnormal seedlings and number of dead seeds were recorded in cloth bag; where the equivalent lowest values were recorded in tin container. The moisture content, 1000-seed weight, electrical conductivity, number of abnormal seedlings and dead seeds were increased with the longer period of storage. In addition, germination index, seedling growth, dry weight per plant of soybean seedling, and vigor index decreased with the increase in storage period. Among the three containers, tin container was the best and the cloth bag was the worst storage container for soybean seed storage for long period. DOI: http://dx.doi.org/10.3329/agric.v12i1.19585 The Agriculturists 2014; 12(1) 85-95

Cladosporium cladosporioides Identified in China on Tobacco Seeds.

Tobacco (Nicotiana tabacum L.) is a leafy, annual, solanaceous plant grown commercially for its leaves. China is the biggest single tobacco market and accounts for more than 40% of the global tobacco consumption (1). Tobacco seed harvested in Guiyang, Guizhou Province, China, are commonly contaminated or infected by various fungal pathogens, which can cause abnormal seedlings with dark brown lesions and stunting of roots and decayed seeds. In 2013, five samples of 500 seeds from tobacco cv. Guiyan 4 were tested for germination on moistened paper on petri dishes. On average, 35% of the seeds from all five samples developed into abnormal seedlings or were decayed and were plated onto potato dextrose agar media and grown for 5 days at 25°C in darkness to confirm the presence of a pathogen. However, one fungus was isolated from an average of 10% of the 500 seeds sampled. It was identified morphologically as Cladosporium cladosporioides (Fresen.) de Vries based on the velvety olive-brown with almost black reverse colony color and dimensions and color of conidia and conidiophores. Conidia formed in long branched chains that readily disarticulate, single celled, elliptical to limoniform, 2 to 8 (avg. 4.3) × 2 to 3 (avg. 2.1) μm. Conidia were pale to olive brown and smooth to verruculose. Ramoconidia were 0 to 1 septate, 7 to 14 (avg. 9.2) × 2 to 4 (avg. 2.6) μm, smooth or sometimes minutely verruculose. Conidiophores were pale to olive brown, macro- and micronemateus, smooth or sometimes verruculose, and of various lengths up to 320 μm long and 2 to 5 μm wide. Primer pair ITS1 and ITS4 was employed to amplify the regions of ITS1-5.8s-ITS2 of the pathogens. Sequences of all three isolates (G3, G10, and G18) (Accession Nos. KF841547, KF841554, and KF841560) were identical to each other and to four sequences in GenBank (JX230994.1, JQ768317.1, JQ768322.1, and AB763555.1). Pathogenicity of the three isolates of C. cladosporioides was verified on tobacco seedlings of 3-week-old grown on wet filter paper in the petri dishes (9 cm in diameter). For each isolate, 20 seedlings incubated in one plate were inoculated with 0.5 ml of a suspension of 105 conidia/ml. Twenty seedlings were treated with sterile water as control treatment. After inoculation, the petri dishes were incubated at 25°C, 100 to 120 μEm-2 S-1, RH > 80%, and 16 h light per day for disease development. At 96 h after inoculation, symptoms comprising medium brown to black lesions on the roots were clearly visible on inoculated plants but not on the control plants. All seedlings inoculated died 9 days after inoculation whereas control seedlings remained symptomless. Re-isolation attempts on PDA from roots demonstrated C. cladosporioides to be present in symptomatic seedlings but not in roots of the control plants. Moreover, the characteristics of the cultured fungi were exactly the same as those originally isolated. Isolates G3, G10, and G18 (KF841547, KF841554, and KF841560) were deposited with the Tobacco Diseased Fungi, Guizhou Academy of Tobacco Sciences, Guizhou, China. Previously, C. cladosporioides has also been isolated from macadamia (Macadamia integrifolia Maiden & Betche) racemes in South Africa (4), from diseased papaya (Carica papaya L.) in Taiwan province of China (2), and from seeds of Amaranthus spp. in Poland (3). To the best of our knowledge, this is the first report of C. cladosporioides causing seed disease on tobacco in China and the disease should be considered in existing disease management practices.

Análise de imagens no estudo morfológico e fisiológico de sementes de abóbora

A obtenção de sementes de abóbora com alta qualidade fisiológica é fundamental para colocar a produção nacional em condições de competitividade com as sementes importadas. Uma técnica que vem sendo utilizada recentemente para estudos relacionados à elucidação de vários aspectos do comportamento das sementes é a análise de imagens, incluindo as obtidas por meio do raio X. Esta técnica consiste em radiografar sementes com o objetivo de avaliar a morfologia interna e, assim, estabelecer relações com o desempenho da semente. O objetivo do presente estudo foi verificar se a técnica de raio X pode ser utilizada com sucesso na detecção de anormalidades e seus reflexos na qualidade fisiológica de sementes de abóbora. Foram utilizadas sementes de abóbora 'Brasileirinha' provenientes de frutos com diferentes estádios de maturação (30, 40, 50 e 60 dias após a antese). Em cada época, as sementes foram extraídas imediatamente após a colheita ou após o armazenamento dos frutos por 15 dias. No teste de raio X as sementes foram submetidas à intensidade de 25 kV por 40 segundos e, em seguida, foi conduzido teste de germinação sob temperatura alternada de 20-30ºC. Após quatro dias foi realizada a primeira contagem e após oito dias a última leitura, computando-se as porcentagens de plântulas normais, anormais e as sementes mortas. Após a obtenção do resultado do teste de germinação foi feita comparação desses resultados com imagens da morfologia interna de cada semente, obtidas por meio do raio X. Foi constatado que a técnica de raio X é eficiente na detecção de sementes mal formadas bem como de sementes vazias de abóbora e estas afetam negativamente sua germinação.

Seleção de lotes de sementes de Pinus taeda L. para a cultura de tecidos

Neste trabalho, objetivou-se identificar os principais gêneros fúngicos associados a três lotes de sementes de Pinus taeda L.; avaliar a qualidade sanitária e fisiológica desses lotes, para utilizar como critério de seleção para a cultura de tecidos e analisar o estabelecimento in vitro de explantes de origem seminal. Foi possível discriminar os lotes quanto à qualidade sanitária e fisiológica, bem como estabelecer in vitro plantas de Pinus taeda, a partir de nós cotiledonares obtidos da germinação asséptica de sementes de um lote selecionado pela qualidade sanitária e fisiológica. Os meios nutritivos MS, ½ MS e WPM são igualmente adequados para esse fim. Para a análise sanitária, os gêneros fúngicos Fusarium, Penicillium e Trichoderma são os de maior sensibilidade. Para a avaliação fisiológica mostraram-se adequadas as variáveis: plântulas anormais, plântulas normais fortes, comprimento, massa fresca e massa seca de plântulas normais fortes. As análises mostraram-se favoráveis à escolha de lotes de sementes para o cultivo in vitro e todos os meios de cultura utilizados foram adequados ao estabelecimento da espécie em cultura de tecidos.

Effect of growing media on seed germination and vigor in biofuel tree species

To evaluate laboratory germination media, seed germination rates and methodology for both Jatropha curcas and Pongamia pinnata were counted in different germination medium, such as river sand, quartz sand and vermiculite. The seeds of both species were sown at 2-cm depth of river sand, quartz sand and vermiculite. We evaluated methodologies of seeds of J. curcas and P. pinnata by ISTA (International Seed Testing Association). The results showed that river sand is the best medium for tree seeds planted at 2-cm depth of River sand. Vermiculite was second best. On paper media, there were many abnormal seedlings and this media were unsuitable for germination of the larger seeds.

Improvement Germination and Conversion of Somatic Embryos and Production of Normal Plantlets in Ferula Assa-foetida L. (A Rare Medicinal Plant)

Secondary somatic embryogenesis leads to the formation of abnormal somatic embryos and produces abnormal seedlings. Normal plants are difficult to obtain from these embryos, due to the asynchronous maturationof the embryogenic tissues and low germination and conversion rates. The effects of some media additives and different strengths of MS medium on germination and plantlet formation of in vitro derived somatic embryos of FerulaAssa-foetidawere studied.The highest number of normal embryos was observed in MS medium containing 30g/l sucrose with 0.5% or 1% AC and in MS medium supplemented with PEG and 0.5% or 1% AC. The treatments of MS medium with 30g/l sucrose and 0.5% AC ◊ MS medium containing sorbitol and MS medium containing PEG and 1% AC ◊ Ω MS had maximum number of normal germinated embryos without secondary somatic embryogenesis (SSE). In some of the treatments the embryos were converted better than the others, such as; the interact ion effect of MS medium with 30g/l sucrose and0.5% AC◊ MS, MS medium with 30g/l sucrose ◊ MS medium with glutamine. Using different strength of MS medium and presence of some media additives is effective on germination and conversion of somatic embryos into normal plantlet. Presence of Activated Charcoal in the culture medium can reduce secondary somatic embryogenesis.

Effect of Osmotic Stress on the Initial Development of Bean Seedlings

One of the methods to determine the tolerance of plants to water stress is the observation of germination of seeds under stress induced in laboratory conditions. Thus, the aim was to evaluate the response of four common bean cultivars to water deficit simulated under laboratory conditions. Two common landrace genotypes acquired from farmers (FORT 07 and FORT 08) and two commercial cultivars, IAPAR 81 and Serrano were evaluated. The different levels of water deficit were induced with mannitol solution. The experimental design was completely randomized and a factorial scheme 5 × 4 (osmotic potential x genotypes), with four replications. The characteristics: primary root protrusion, seed vigor, normal and abnormal seedling, seedling and root length, fresh and dry weight of seedling and root were evaluated. By reducing the osmotic potential seedling vigor bean was more affected than the primary root protrusion. Regardless of cultivar, there was a significant and progressive reduction in the normal seedlings percentage from potential -0.3 MPa. The IAPAR 81 and FORT 07 cultivars showed higher tolerance to water deficit compared to other cultivars.

Halopriming and Hydropriming Treatments to Overcome Salt and Drought Stress at Germination Stage of Corn (Zea mays L.)

To study the effects of halopriming and hydropriming in overcoming salt and drought stress in corn (Zea mays L.),two experiments were separately conducted at Shahrood University of Technology. Seed treatments consisted ofcontrol (untreated seeds), soaking in distilled water for 32 h (hydropriming), and soaking in 50 mmol solution ofCaCl2 for 16 h (halopriming). Germination and early seedling growth were studied using distilled water (control) andosmotic potentials of -0.4, -0.8, and -1.2 MPa from NaCl (salinity stress) and polyethylene glycol [PEG 6000(drought stress)]. Results showed that in both salinity and drought experiments, germination percentage reducedsignificantly according to decreased osmotic potential. Hydroprimed and haloprimed seeds achieved the minimumreductions in germination percentage. The maximum reduction in germination percentage was recorded fromuntreated seeds (control). Minimum reduction percentages of root length (RPL root) and shoot length (RPL shoot)were attained from hydroprimed and haloprimed seeds due to NaCl and PEG conditions (-0.4 MPa), and maximumRPL root and RPL shoot were attained from controlled seeds due to NaCl and PEG (-1.2 MPa) conditions. Thereduction percentage of dry weight for root (RPD root) and shoot (RPD shoot) increased according to increasedosmotic potential in both NaCl and PEG, but RPD for shoot was significantly affected compared with RPD for root.Interaction of seed priming treatment and osmotic potential for the germination index (GI) showed that under 0 and -0.4 MPa, hydroprimed and haloprimed seeds had higher GI as compared with untreated seeds due to NaCl and PEGconditions. Interaction between the seed priming treatment and osmotic potential significantly affected the vigourindex (VI) due to NaCl and PEG conditions, and halopriming significantly increased VI at high osmotic potentials.On average, the VI of haloprimed seeds was higher than that of untreated seeds at high osmotic potentials and wasnot significantly different from hydroprimed and untreated seeds at low osmotic potentials. It is concluded that undersalinity stress, the osmotic effect is more important than the toxic effect in loss of seed germination. Moreover,hydropriming practically ensured rapid and uniform germination with few abnormal seedlings.

Examination quality seed perennial ryegrass, Italian ryegrass and red fescue

Examination is seed quality of perennial ryegrass (Lolium perenne), italian ryegrass (Lolium multiflorum) and red fescue (Festuca rubra) during the five years 2010 - 2014. The average established seed purity was over 98.40%, with varying by year from 96.7% to 99.2%. The greatest part of the impurities was inert matter, which are varied over the years in the range from 0.0% to 2.30%. Presence of weed seeds by year varied in the range from 0.0% to 0.50%. In the seeds of the tested grasses dominate the weeds from the family Asteraceae, Caryophillaceae, Chenopodiaceae and Polygonaceae. The most common weeds in the investigated grasses were Amaranthus retroflexus and Chenopodium album. Participation of other species by year ranged from 0.0% to 1.8%. Seed germination varied from 75 to 88%, the average was 83%. The number of abnormal seedlings was 4%, while the average number of ungerminated seeds was 13%.

Pathogenicity of phylogenetic species in the Fusarium graminearum complex on soybean seedlings in Argentina

Soybean (Glycine max L.) is one of the main crops in Argentina. Most of the studies of pathogenicity in the Fusarium graminearum complex have focused on strains isolated from wheat and maize, and there is little information on strains isolated from soybean. Our objective in the present study was to compare the pathogenicity among soybean isolates of different phylogenetic species within the Fusarium graminearum complex on soybean seedlings under controlled conditions. Six strains representing three different phylogenetic species (F. graminearum, F. meridionale and F. cortaderiae) were identified by partial sequencing of the Translation Elongation Factor -1α gene (TEF-1) and evaluated for pathogenicity. All six strains reduced emergence, mainly by causing pre-emergence damping-off, seedling height and root dry weight and produced abnormal seedlings. The mean disease severity averaged across all isolates was approximately 3.0 in a 0–4 rating scale where 0 = healthy seedling and 4 = dead seedling. Significant differences in pathogenicity were observed among F. graminearum, F. meridionale and F. cortaderiae. These results are consistent with the hypothesis that different phylogenetic species within the Fusarium graminearum complex isolated from soybean are pathogenic under controlled conditions to soybean seedlings in Argentina. The present study demonstrates for the first time the pathogenic effect of F. meridionale on soybean in Argentina.

Abnormal Seedlings Emerged during Embryo Rescue and Its Remedy for Seedless Grape Breeding

The abnormal seedlings, a common physiological anomalies, emerged during embryo rescue severely restricted grape breeding. To enhance the efficiency of the seedless grape breeding by reducing the production of abnormal seedlings in the course of embryo rescue, we investigated the effects of genotype, media type, embryo style, pre-chilling on the deformity rate of the abnormal seedlings during embryo rescue. The abnormal seedlings were firstly classified into seven categories based on their morphology. Our results indicated that the emergence of abnormal seedlings was highly dependent on the female parent genotype. Polyembryony was advantageous to diminish the number of abnormal plantlets and the germination rate of embryo was 100%. We also found that pre-chilling treatment could reduce the number of abnormal plantlets and promote the embryo germination. The abnormal plantlets were reduced significantly by the addition of ZnSO₄ 10 μmol?L -1 or mashed-banana 500 mg?L -1 to either embryo development or germination media. Transferring the abnormal seedlings onto the suitable fresh media in 4 weeks after embryo germination provided an effective way to transform them into normal seedlings.

Seed Borne Mycoflora of Some Commercial Wheat (Triticum aestivum L.) Cultivars in Punjab, Pakistan

Seed borne mycoflora associated with ten commercial varieties of wheat viz. Blue silver, Faisalabad 85, Manthar-3, Pak 81, Parwaz 94, Pirsabaq 2005, Punjnad-1, Sariab-92, Sh-2002 and Wafaq-2001 was investigated through standard blotter paper and agar plate method by using Mann-Whitney U test. At least eleven fungal genera were recovered from seeds. The most frequently isolated fungi were Bipolaris sorokiniana (11.125%), Aspergillus flavus (9.825%), Alternaria alternata (7.15%) and Aspergillus niger (6.225%). It is apparent from the present investigation that all commercial wheat verities tested were contaminated by fungi. The rolled paper method was used to find out the effect of seed borne fungi on seed germination. Seeds of Pak 81, Wafaq-2001 and Blue silver were germinated in high proportion with variable number of normal and abnormal seedlings than the seeds of other varieties tested. The fungi associated with seeds of wheat cause dire diseases in wheat reducing the germination capacity.

Evaluating antimutagenic effects of vitamin‐C and L‐cysteine alone and in combination towards sodium azide‐induced toxicity in Trigonella foenum‐ graecum L.

Antimutagenicity of vitamin‐C (ascorbic acid) and L‐cysteine (amino acid) was determined against the mutagenicity of sodium azide (NaN3; pH 6.0) in Trigonella foenum‐graecum L. Toxicity to seed germination and seedling growth were taken as as the parameters. Sodium azide (mutagenic agent) induces inhibitory effects on the seed germination and causes formation of abnormal seedlings significantly with increasing concentrations. Sodium azide mutagenized seeds of T. foenum‐graecum post‐treated with four different aqueous concentrations of vitamin‐C (0.0005M, 0.0010M, 0.0015M and 0.0100M) and L‐cysteine (0.0005M, 0.0010M, 0.0015M and 0.0100M), exhibited antimutagenic activity by way of promotory effects on seed germination as well as on seedling growth as compared to contol. L‐cystein was found to be more potent as antimutagen (antitoxic) than vitamin‐C.

Effect of Seedling Raising Shelf Size on Seedling Growth of Rice

Rice seedling raising in shelf apparatus not only saves time but also reduces labor input. However. it sometimes gives weak seedling because of light shading during the seedling growth in shelf. To develop technology for healthy seedling growth in seedling raising shelf, the effect of seedling raising shelf width and Interlayer on seedling growth of rice(cv.Gumyoung) at 95 cm and 125 cm 1n width such as 35 cm, 50 cm and 65 cm Interlayer, respectively was investigated. The seedling quality of rice and occurrence of abnormal seedling on rice seedling were not greatly different in shelf widths, but those were significantly different among shelf Interlayers. As shelf hight was rising, the seedling quality of rice and occurrence of abnormal seedling on rice seedling were increasing and decreasing, respectively. And the rice seedling grown in the seedling raising shelf making with 95cm and 125cm in width by 50cm and 65cm in Interlayer gave better seedling quality and lower occurrence of abnormal seedling on the rice seedling than that grown in the conventional seeding raising shelf with 65cm in width by 20cm in Interlayer. The making shelf with 95cm in width by 65cm in Interlayer and that with 125cm in width by 65cm in Interlayer reduces the cost and expense for shelf body-making and re-moving of growing box etc. based on 1,000 boxes by 24~78% versus the conventional seedling shelf.

Potencial alelopático do extrato aquoso de sementes de mulungu (Erythrina velutina Willd.)

The Erythrina velutina Willd has a great resistance to drought, has medicinal properties and allelopathic effect; so the aim of this study was to evaluate the allelopathic activity of aqueous extract of seeds of E. velutina in different concentrations on seed germination and seedling development of lettuce (Lactuca sativa L.). Two experiments (a standard extract obtained with water at 25 °C and the other at 100 °C) were conducted in completely randomized design with five concentrations (control - distilled water, 25, 50, 75 and 100%) with four replicates of 25 seeds. The percentage and germination speed index (IVG), percentage of normal and abnormal seedlings, shoot and root length of lettuce seedlings were evaluated. The germination percentage was low (25 and 8%) in the extraction at 25 and 100 °C respectively, when 100% concentration of the extract was used. The percentage of abnormal seedlings was high, reaching 100% at all concentrations except for the extract at 25 °C and at a concentration of 25%. The extracts from E. velutina seeds have allelopathic activity on germination and growth of lettuce.

Physiological Quality of Cowpea Seeds Produced in Southwestern Nigeria

The experiment was conducted at the Institute of Agricultural Research and Training, Obafemi Awolowo University, Moor Plantation, Ibadan to determine the physiological qualities of cowpea seeds produced in rain forest environment. Six varieties of cowpea produced in two different locations were collected from the Legume Improvement Programme of the Institute. There were two experiments for this study. Electrolyte leakage was determined using 3 replicates of 50 pre weighed seeds with JENWAY 4510 digital electrical conductivity meter, while sterilized river bed sand was used for standard germination. All laboratory tests were conducted using the complete randomized design (CRD). The results showed that variety and location had significant (p<0.05-0.001) effects on germination percent (GCPT), germination rate index (GRI) and seedling length. Interaction between variety and location also had significant (p<0.01) effects on GCPT, GRI and seedling length. There were significant differences (p<0.05) among the varieties with respect to the germination percent. GCPT ranged from 66.67% in IT90k-227-2 to 92.67% in Ife BPC with overall means of 78.33. GCPT was higher in cowpea seeds produced in Ibadan than that produced in Ile-Ife. Number of abnormal seedlings was not statistically different from one another. Overall germination percent of the cowpea produced in Ibadan was 88.44% and the percentage was lower in Ile-Ife. Results also revealed that conductivity value was low in seed produced in Ibadan which is an indication of high quality seed over those produced in Ile-Ife. From the results of this experiment it can be deduced, that high quality seeds of cowpea can be produced in Ibadan and some other parts of the State that fall under transition environment.

Techonolgy of Qualea grandiflora Mart. (Vochysiaceae) seeds

Qualea grandiflora Mart. (Vochysiaceae), commonly known as "pau-terra", is an arborous species native to the Brazilian savannah which possess commercial interests, as it can be used either as an ornamental or as a medicinal plant. "Pau-terra" can also be used in the heterogeneous reforestation of areas which are destined for restoration of permanent preservation degraded areas. Propagation studies with this species are scarce, being necessary then further clarification regarding the factors that influences the germination process. In this context, the objective of this work was to evaluate the influence of different temperatures, substrates and light conditions on seed germination. We selected light brown seeds which were subjected to different interactions between temperatures (15-25, 20-30, 25 and 30°C), substrate (paper, sand and vermiculite) and light (light and dark). All seeds were later dry-incubated at 32°C for 3, 6 and 12 hours. After treatments, seeds were kept in BOD at 58% RH and the following parameters were calculated: germination (%G) and germination speed index (GSI); the formation of normal and abnormal seedlings and the number dead seeds. Interaction was observed for all variables. In the optimum temperature range, the seeds behaved as photoblastic neutral or indifferent. Under alternating temperatures, darkness enhanced the germination, especially when combined with the lower temperatures. We noted that the sowing in sand, at 25°C, allowed the maintenance of suitable combinations of germination and seedling development. With respect to desiccation tolerance, "pau-terra" seeds presented an orthodox behavior, with a linear increase of the vigor as function of drying.