scholarly journals Peer Review #2 of "Maintenance of dominant populations in heavily grazed grassland: Inference from a Stipa breviflora seed germination experiment (v0.1)"

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Yongji Wang

To explore the optimum temperature, light intensityand water conditions for seed germination of Siphonostegia chinensis Benth.,seed germination experiment were carried out under different temperatures(5/15, 10/20, 15/25, 20/30℃), different light intensity(14h light/10h darkness, complete darkness)and different concentrations(0%, 5%, 10%, 15%, 20%)of PEG-6000 solution. In terms of concentration, 5% PEG was regarded as the low level, 10% and 15% as the medium level, and 20% as the high level. The results showed that (1) Germination rate, germination potential, and germination index were increased with the rise of temperature. In addition, seed germination was significantly higher under the dark conditions than that with the 14h light/10h darkness. (2) No seed germination occurred when the temperature was below 10/20 ºC at 14h light/10h darkness. (3) Under 14h light/10h darkness, the germination rate, germination potential and germination index first increased and then decreased with the increase of PEG concentration. The low concentration was more beneficial to the seed germination. (4) Under the condition of complete darkness, the germination rate, germination potential and germination index decline with fluctuation with the increase of PEG concentration. Seed germination of Siphonostegia chinensis Benth. was inhibited in high concentration of PEG.


2020 ◽  
Vol 21 (9) ◽  
Author(s):  
Loekas Soesanto ◽  
Annisa Rahmaddila Rizky Hartono ◽  
Endang Mugiastuti ◽  
Heri Widarta

Abstract. Soesanto L, Hartono ARR, Mugiastuti E, Widarta H. 2020. Seed-borne pathogenic fungi on some soybean varieties. Biodiversitas 21: 4010-4015. The present study was conducted to detect and identify seed-borne pathogenic fungi in some soybean varieties and their effect on seed germination. Experiment was performed in a completely random design with eight treatments and four replicates. Eight soybean varieties i.e., Malabar, Kaba, Dering, Detam I, Sinabung, Dena, Gepak Kuning, and Slamet were selected for the investigation. Seed borne fungi were isolated using blotter test and agar plate techniques. The variables observed were morphological/cultural characteristics, microscopic features of fungi, and percentage of seed germination. A total of eight fungi namely Aspergillus flavus Link, Aspergillus niger van Tieghem, Cladosporium oxysporum Berk. & M.A. Curtis, Colletotrichum dematium (Pers. et Fr.) Grove f.sp. truncate (Schw.) Arx, Curvularia pallescens Boedijn, Fusarium solani (Mart.) Sacc., Melanospora zamiae Corda, and Nigrospora sp. Mason were isolated from different varieties of soybean seeds. The highest seed germination was found to be 80.5% in Daring and Detam I varieties, respectively, and the lowest 53% was recorded in Dena variety.


2013 ◽  
Vol 29 (2) ◽  
pp. 123-130 ◽  
Author(s):  
Ana María Benavides ◽  
Jan H. D. Wolf ◽  
Joost F. Duivenvoorden

Abstract:The contribution of vegetative recruitment by non-tree species to the regeneration of tropical forests in man-made clearings or tree-fall gaps tends to be ignored. In a series of field studies near Amacayacu, Colombian Amazonia, we tested if hemiepiphytic aroids quickly colonize such open habitats through seed dispersal, sprouting plant fragments, or lateral invasion of flagellar aroids from the closed forest nearby. A seed germination experiment applying two soil substrates and three shade levels showed that abundant light reduced the germination success of three Philodendron species. A total of 400 cuttings from five Philodendron species were placed in forest clearings and almost 12% of these sprouted within 14 wk. Monitoring more than 2000 aroid plants over 14 mo in different habitats showed that recruitment was low (0.3 plants per 10 m2) compared with initial densities (3.1 plants per 10 m2). Flagellar aroids grew about 2.5 times faster than non-flagellar aroids. In forest edges they reached a mean apical growth of 98 cm in 14 mo. However, non-flagellar aroids were five to six times more abundant than flagellar individuals everywhere. It was concluded that hemiepiphytic aroids colonize open habitats mostly through a post-disturbance survival of plants or plant fragments.


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