Lettuce seedling growth: Antagonism between gibberellic acid and Niacin

1971 ◽  
Vol 27 (10) ◽  
pp. 1163-1164 ◽  
Author(s):  
Prakash Mullick ◽  
U. N. Chatterji
Keyword(s):  
Gibberellic Acid ◽  
Seedling Growth ◽  
Lettuce Seedling

Dormancy, germination and seedling growth of two Kalaharian perennials of the genus Harpagophytum (Pedaliaceae)

1988 ◽  
Vol 4 (2) ◽  
pp. 185-198 ◽  
Author(s):  
W. H. O. Ernst ◽  
T. Tietema ◽  
E. M. Veenendaal ◽  
R. Masene
Keyword(s):  
Gibberellic Acid ◽  
High Temperatures ◽  
Seedling Growth ◽  
Seed Coat ◽  
Growth Rates ◽  
Natural Conditions ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Respiration Rates ◽  
Drought Avoidance

ABSTRACTDormancy and germination ecology of two Harpagophytum species (Pedaliaceae) from an open Acacia savanna in Botswana were investigated. The maintenance of dormancy is governed partly by the seed coat but mainly by the endosperm and the embryo itself, as demonstrated by removal of the endosperm. Dissemination of the seed from the fruit can be delayed for several years without affecting the viability of the embryo, due to very low respiration rates.Germination can be enhanced slightly by high temperatures under natural conditions, and by gibberellic acid or removal of the endosperm under laboratory conditions. Relative growth rates for both Harpagophytum species are lower than for subtropical grasses and legumes, due to a strong investment in root and tuber biomass. Germination and seedling growth is discussed in relation to the drought avoidance syndrome and the animal disperser syndrome.

Relative phytotoxicity of parthenium weed (Parthenium hysterophorus L.) residues on the seedling growth of a range of Australian native and introduced species

2018 ◽  
Vol 69 (8) ◽  
pp. 837 ◽  
Author(s):  
Boyang Shi ◽  
Steve Adkins
Keyword(s):  
Seedling Growth ◽  
Invasion Success ◽  
Parthenium Hysterophorus ◽  
Grass Species ◽  
Pasture Grass ◽  
Lettuce Seedling ◽  
Non Invasive ◽  
Significant Difference ◽  
Phytotoxic Effect ◽  
Parthenium Weed

The invasive herbaceous species Parthenium hysterophorus L. (Asteraceae), commonly known as parthenium weed has rapidly become a significant weed in more than 30 countries. Parthenium weed litter taken from the introduced biotypes was relatively more phytotoxic than that taken from biotypes coming from the native range when tested on lettuce and this may indicate one reason for invasion success. However, no significant difference was observed in phytotoxicity to lettuce seedling growth when two Australian biotypes of parthenium weed were compared, one invasive and one non-invasive, indicating that invasiveness was not associated with litter phytotoxicity in all cases. Residue from the invasive parthenium weed biotype had a greater phytotoxic effect upon Australian native pasture grass species relative to the introduced pasture grass species with buffel grass (Cenchrus ciliaris L.) and bull Mitchell grass (Astreble sequarrosa C.E.Hubb) showing the greatest tolerance to parthenium weed phytochemicals. When compared with residue taken from plants that has a range of phytotoxic capacity, parthenium weed residue was considered to be only moderately phytotoxic suggesting that the phytotoxicity of its residue may not be the main reason for the plants invasive trait.

scholarly journals Effect of pre-germinative treatments on Nothofagus glauca seed germination and seedling growth

2019 ◽  
Vol 49 ◽  
Author(s):  
Ángel Cabello ◽  
Nicolás Espinoza ◽  
Sergio Espinoza ◽  
Antonio Cabrera ◽  
Rómulo Santelices
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
Seedling Growth ◽  
Iucn Red List ◽  
Cold Stratification ◽  
Natural Forests ◽  
Sowing Time ◽  
High Germination ◽  
Thiourea Solution ◽  
Quality Stock

Background: Nothofagus glauca (Phil.) Krasser (Nothofagaceae, “Hualo”) is an endemic tree of the Mediterranean zone of Chile. The natural forests in this area have been severely fragmented as a result of human causes such as replacement by agricultural crops and fast-growing tree species. From 1975, these forests have declined from 900,000 ha to 145,000 ha, so it is categorised on the IUCN Red List as ‘vulnerable’. In restoring this ecosystem, efforts should focus, in part, on the propagation of quality stock. However, information on propagation systems is still insufficient. Methods: We aimed to analyse the effect of different pre-germinative treatments and sowing times on seed germination, and seedling growth and quality. The pre-germinative treatments were: (i) cold stratification; (ii) soaking in gibberellic acid (GA3) and thiourea solution; and (iii) nursery cultivation, while the sowing times were July, August and September. Results: A high germination capacity was achieved by: soaking the seeds in GA3 solution irrespective of concentration; stratifying, irrespective of period; or soaking in 7.5 mg L-1 thiourea solution, values significantly varied from that of the control treatments. The sowing time was not relevant in terms of the percentage of germination or seedling development. Stratification at 5°C for 60 days produced the best quality indices for N. glauca seedlings but no significant differences were found in any of the morphological attributes tested as a result of the pre-germinative treatments. Conclusions: The pre-germinative treatments significantly improved the germination and seedlings growth of N. glauca. Cold stratification at 5°C for 60 days is recommended as it produced suitable seedlings for field establishment. Gibberellic acid and thiourea did not produce important effects on seedling growth. Our results suggest the presence of endogenous physiological dormancy of the N. glauca seeds. The results of this study provide important information on propagation and nursery techniques of N. glauca, which can be used in restoration programmes.

scholarly journals The Effect of Hormone Seed Priming Using Gibberellic Acid on Seed Germination Characteristics and Seedling Growth of Coneflower (Echinacea purpurea)

2021 ◽  
Vol 8 (1) ◽  
pp. 173-188
Author(s):  
Farshid Yousefi ◽  
Abdolreza Sihampoosh ◽  
Abdolmahdi Bakhshandeh ◽  
Seyyed Amir Mousavi ◽  
◽  
...  
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
Seedling Growth ◽  
Seed Priming ◽  
Echinacea Purpurea ◽  
Germination Characteristics
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