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Previous issue date: 2008-02-28 / Germination, conservation and physical characteristics of seeds of four cacti species that
occurs on Rio de Janeiro State coastal regions, Cereus fernambucensis Lem.,
Coleocephalocereus fluminensis (Miq.) Backeb., Pilosocereus arrabidae (Lem.) Byles
& G.D. Rowley and Pilosocereus ulei (K. Schum.) Byles & G.D. Rowley were
evaluated in this study. The first experiment, mounted in a completely randomized
design and factorial system, tested two substrates (agar 1% and paper) and three
temperatures (20?C, 25?C and 20-30?C) using four replicates of 40 seeds. The
evaluation parameters were germination percentage (normal seedlings) and germination
average time (ANOVA and Tukey; P<0,05). According to the germination analysis, the
best combination of temperature and substrate is 20?C in agar for C. fernambucensis,
20?C and 20-30?C in paper or agar for C. fluminensis, 25?C in agar for P. arrabidae and
20, 25 and 20-30?C in paper, as well as, 20 and 25?C in agar for P. ulei. The use of agar
1% was suitable for germination of this cacti seeds, being necessary, however, studies
that lead to reduction in the incidence of plant health problems. In another experiment
the effects of storage and seed water content were evaluated on the germination
percentage and germination average time of these four species. To better define the salts
to be used in the seed drying process for this experiment, adsorption isotherms were
built using static gravimetric method, with saturated salt solutions. The isotherms of all
species showed a reverse sigmoidal pattern with increase of seed water content
according to the increase in relative humidity. In the conservation experiment, also
arranged in completely randomized design and factorial system, three different storage
conditions (control, 30 days at 10?C and 30 days at -196?C) under three levels of water
content, around 5, 7 and 9% (dry basis) were tested, with four replicates of forty seeds
(ANOVA and Tukey; P<0,05) at the following conditions: C. fernambucensis in agar at
20?C, C. fluminensis and P. ulei in paper at 20?C and P. arrabidae in agar at 25?C. All
four species showed dehydration and sub-zero temperature tolerance. Seed viability and four species showed dehydration and sub-zero temperature tolerance. Seed viability and
vigour showed no changes when stored with water content around 7%, at 10?C and
cryopreserved at -196?C. Cryopreservation can be recommended for the storage of this
cacti species. / As caracter?sticas f?sicas, germina??o e conserva??o de sementes de quatro esp?cies de
cact?ceas ocorrentes nas ?reas litor?neas do estado do Rio de Janeiro, Cereus
fernambucensis Lem., Coleocephalocereus fluminensis (Miq.) Backeb., Pilosocereus
arrabidae (Lem.) Byles & G.D. Rowley e Pilosocereus ulei (K. Schum.) Byles & G.D.
Rowley foram avaliadas neste estudo. O primeiro experimento, montado em
delineamento inteiramente casualizado e esquema fatorial, testou dois substratos (?gar
1% e sobre papel ) e tr?s temperaturas (20?C, 25?C e 20-30?C) utilizando quatro
repeti??es de 40 sementes. Os par?metros de avalia??o foram porcentagem de
germina??o (pl?ntulas normais) e tempo m?dio de germina??o (ANAVA e Tukey;
P<0,05). De acordo com a an?lise de germina??o, as melhores temperaturas e substratos
para a germina??o de sementes de C. fernambucensis s?o 20?C e ?gar; para C.
fluminensis, 20?C e 20-30?C, tanto no substrato papel como em ?gar, para P. arrabidae,
25?C em ?gar e para P. ulei em papel a 20, 25 e 20-30?C e ?gar a 20 e 25?C. O uso de
?gar 1% se mostrou adequado a germina??o das sementes destas cact?ceas, sendo
necess?rios, no entanto, estudos que levem a redu??o da incid?ncia de problemas
fitossanit?rios. Em outro experimento foram avaliados os efeitos de armazenamento e
teor de ?gua das sementes sobre o percentual e o tempo m?dio de germina??o destas
quatro esp?cies. Para melhor defini??o dos sais a serem usados na secagem das
sementes para este experimento, foram constru?das isotermas de adsor??o utilizando-se
o m?todo gravim?trico, est?tico, com solu??es salinas saturadas. As isotermas de todas
as esp?cies revelaram um padr?o sigmoidal inverso com o acr?scimo de teor de ?gua
das sementes em fun??o do aumento da umidade relativa do ar. No experimento de
conserva??o, tamb?m montado em delineamento inteiramente casualizado e esquema
fatorial, foram testadas tr?s diferentes condi??es de armazenamento (controle, 30 dias a
10?C e 30 dias a -196?C) sob tr?s diferentes teores de ?gua, pr?ximos a 5, 7 e 9% (base
seca), utilizando quatro repeti??es de 40 sementes (ANAVA e Tukey; P<0,05) e nas
seguintes condi??es: C. fernambucensis em ?gar a 20?C, C. fluminensis e P. ulei em
papel a 20?C e P. arrabidae em ?gar a 25?C. As quatro esp?cies demonstraram
toler?ncia a desidrata??o e a temperatura sub-zero. A viabilidade e o vigor das sementes
n?o apresentaram altera??es quando armazenados com teores de ?gua pr?ximos a 7%,
tanto em c?mara fria a 10?C como criopreservado a -196?C. A criopreserva??o pode ser
recomendada para o armazenamento das esp?cies estudadas.
| Identifer | oai:union.ndltd.org:IBICT/oai:localhost:tede/521 |
| Date | 28 February 2008 |
| Creators | Almeida, Tha?s Moreira Hidalgo de |
| Contributors | Lopes, Higino Marcos, Andrade, Antonio Carlos Silva de |
| Publisher | Universidade Federal Rural do Rio de Janeiro, Curso de P?s-Gradua??o em Fitotecnia, UFRRJ, Brasil, Produ??o Vegetal |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFRRJ, instname:Universidade Federal Rural do Rio de Janeiro, instacron:UFRRJ |
| Rights | info:eu-repo/semantics/openAccess |
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