Germination Of Cotton Seeds Research Articles

Preparation, characterisation and some properties of saponins from lucerne tops and roots

AbstractLucerne saponin extracts have been prepared from lucerne tops and roots by two different methods. The root extracts possess stronger haemolytic activity and to a certain extent are stronger foaming agents than those from the tops. Thin‐layer chromatographic (t.l.c.) analyses showed that acid hydrolysates of the different preparations contain soyasapogenols A, B, C, D, E, medicagenic acid and an unidentified sapogenin‐like spot. When submitted to t.l.c. and paper electrophoresis the first pair of extracts have been separated into six fractions each, and the other extracts into seven fractions each. The root extract and to a lesser extent that from the tops, depress growth of Tribolium castaneum larvae but the inhibitory effect can be reversed when cholesterol is incorporated in the diet. Germination of cotton seeds is inhibited in soils on which lucerne has been grown or on soils supplemented with lucerne meal from tops and roots.

Effect of Direct Current Glow Discharge on Germination of Cottonseed

Effect of Direct Current Glow Discharge on Germination of Cottonseed

INTERNAL CONTROL IN DETERMINING OF SEED RAW COTTON YIELD

Laboratory and field experiments were carried out at the experimental site of the Research Institute of Breeding, Seed Production and Agricultural Technology of Cotton Growing, located in the Kibray District of the Tashkent Region at 42 degrees north latitude, at an altitude of 481 m above sea level. The soil is a typical, cultivated gray soil of old irrigation from the Boz-Su main channel. Agrotechnical measures were carried out in accordance with the recommendations of the Uzbek Cotton Research Institute for the conditions of typical gray soils with deep groundwater. For each fruit branch the weight of one capsule, the number and weight of 1000 seed pieces were determined under laboratory conditions, their germination. It is shown that the high quality of cotton seeds guarantees control over their varietal and sowing characteristics. The yield, and therefore the number and size of the bolls are influenced by many factors – climate, soil, growing zones, annual rates of NPK mineral fertilizers, irrigation regime, agrotechnical methods, and others. Most of all yield volume depends on the rate of application of mineral fertilizers. On sown areas the field germination of cotton seeds, as a rule, is no more than 75-80%. Bringing it to 90% and above will provide the most complete plant stand density, while the seeding rate will decrease and the weight of 1000 seed pieces will increase. It was revealed that this indicator in comparison with the number of seeds in one seed capsule by the tightness of the connection, is characterized by a curvilinear dependence with a correlation ratio η = 0.885. The closeness of the connection between the field seeds germination and the opening of the capsules was established: with it’s increasing the percentage of opening decreases.

Physical Factors Affecting Oxygen Stress of Germinating Cotton Seeds

Physical Factors Affecting Oxygen Stress of Germinating Cotton Seeds

The influence of temperature on the exudation of nutrients from cotton seeds and on preemergence damping-off by Rhizoctonia solani

Evidence is presented suggesting that increased seed exudation is a major factor contributing to increased preemergence damping-off of cotton seedlings by Rhizoctonia solani at low temperatures.About seven and three times as much total amino acids and sugars were exuded at 18 and 24 °C, respectively, as at 30 °C, by germinating cotton seeds of equivalent physiological age. Sixteen amino acids and five sugars were exuded. Seed exudation is not related to rate of germination or to respiration.Accumulation of seed exudate at low temperatures was related to increased pathogenesis in vitro and in soil. This appeared to be because R. solani competitively used this exudate to increase its inoculum potential near the germinating seed, thereby becoming more virulent on the susceptible juvenile tissues of the seedling.

Development of Photosynthesis in Cotton Seedlings, Gossypium hirsutum L.1

An infrared gas analyzer was used to follow CO2 exchange (dark respiration and net photosynthesis) through the first 248 hr of germination of cotton seeds. The following events were noted: (a) dark respiration was first detectable 6 hr after placing the dry seed in water (planting); (b) the photosynthetic cempensation point was reached 86 hr after planting and 24 hr after emergence and occurred during the unfolding of the cotyledonary leaves; (c) maximum rates of net photosynthesis (33 mg CO2/dm2/hr at 64.8 kilolux with 500 ppm CO2) were attained by 200 hr after planting and remained at this level during the remainder of the test period (48 hr); and (d) photosynthetic rates increased as light and CO2 concentrations were increased. The fully expanded cotyledonary leaf stage (200 to 248 hr after planting) of the cotton seedling is suitable for photosynthetic studies cause of the stability and uniformity of the photosynthetic rate.General Electric Cool Beam lamps were found to be equally as effective as sunlight in providing energy for fixation of CO2.Dark respiration rates, determined throughout the experiment, increased from 0 to a maximum by 120 to 130 hr after planting and remained constant for the next 24 hr.

Ribonucleic acid synthesis in germinating cotton seeds

The synthesis of RNA has been mapped during the initial (dark) phase of germination in cotton seed. During the first 16 hours whole embryos synthesize new ribosomes and protein. Treatment of whole embryos with cycloheximide during this period inhibits protein synthesis and stops further development. Actinomycin D inhibits the synthesis of new ribosomes. This inhibition does not decrease the total ribosomal population, inhibit the synthesis of protein, or retard normal development during this time. These observations suggest that the protein synthesis observed during this period is directed by stable messenger RNA and ribosomes which exist preformed in the mature seed. The synthesis of ribosomes ceases after about 40 hours in the cotyledons and 48 hours in the roots and stems. After this time the synthesis of ribosomal RNA continues but it does not become incorporated into ribosomes. Rather, this RNA is incorporated into a particle, detectable only by radioactivity, which sediments more slowly than monomeric ribosomes on a sucrose density-gradient. On prolonged incubation, the radioactivity associated with the particle moves into mature ribosomes. The particle appears to be an intermediate in the synthesis of ribosomes and has properties similar to those reported for ribosomal precursor particles in bacteria. Its synthesis is completely suppressed by light. During the period of precursor particle synthesis in the roots and stems, protein and RNA synthesis is necessary for further development as determined by inhibition studies with cycloheximide and actinomycin D. The required RNA synthesis is possibly messenger RNA. In cotyledons, during this period, protein synthesis appears to be required for normal development. Whether this protein synthesis is dependent upon concurrent RNA synthesis cannot be evaluated by the use of actinomycin D, probably due to an inability to get the antibiotic into the cells during this period.

Ribosomal-RNA Synthesis in the Absence of Ribosome Synthesis in Germinating Cotton Seeds

Cotton embryos after 72 hours of germination synthesize ribosomal RNA that does not become incorporated into ribosomes and that is very stable. This RNA has many characteristics similar to those of newly synthesized ribosomal RNA of bacteria.

LONG-LIVED MESSENGER RNA: EVIDENCE FROM COTTON SEED GERMINATION.

In germinating cotton embryos the partial inhibition of RNA synthesis by actinomycin D does not inhibit the incorporation of leucine-(14)C into soluble protein nor cause a loss of polyribosomes during the first 16 hours of germination. This suggests that the protein synthesis observed during this period is directed by messenger RNA which exists in the mature seed and which is not rapidly degraded and resynthesized.

Laboratory and Field Investigations with Phorate-Treated Cotton Seeds1

The absorption of P32-labeled prorate by cotton seeds was investigated under laboratory, greenhouse, and field conditions. Dehulled seeds absorbed much more phorate than intact seeds; however, this increased amount of phorate in the dehulled seed did not reduce germination or radical growth. Absorption of inorganic P32 was not appreciably inhibited by the seed coat. Water absorption and respiration of germinating cotton seeds was not markedly different between untreated and treated seeds. Cotton plants grown in sand and soil from prorate-treated seeds absorbed 2% to 6% of the applied dosage, chiefly during the first 7 days after planting.

Fat Utilization and Composition in Germinating Cotton Seeds.

Fat Utilization and Composition in Germinating Cotton Seeds.

Adubação do algodoeiro: I - Influência dos adubos, quando aplicados em contato com as sementes, sobre a germinação

Os autores do presente artigo relatam os resultados de um ensaio realizado cm 1936-37, na Estação Experimental Central, para estudar a influência de alguns adubos sobre a germinação das sementes do algodoeiro. Para isso foram estabelecidas comparações entre canteiros sem adubo e canteiros adubados com 0-50-0, 0-50-50 e 10-50-50 kg/ha de N-P2O5-K2O e, ainda, com outros que receberam o dôbro dessas doses. N e K2O foram empregados respectivamente nas formas de salitre do Chile e cloreto de potássio: P2O5, em cada uma das três formas: farinha de ossos, Renania-fosfato e superfosfato. Comparou-se, também, a aplicação desses adubos nas covas e nos sulcos de plantio. Os 38 tratamentos do ensaio tiveram três repetições. Cada canteiro, de 25 m², constou de uma fileira de 20,90 m, espaçada de 1,20 m das vizinhas. Nas fileiras, 53 covas propriamente ditas foram plantadas a cêrea de 0,40 m uma das outras, cada cova recebendo seis sementes; no plantio em sulcos, de 0,40 em 0,40 m foram depositadas seis sementes. As correspondentes doses de adubo foram aplicadas em cada cova ou distribuídas continuamente nos sulcos, e, após ligeira mistura com a terra, semeou-se no solo adubado. Durante 36 dias a partir do plantio foram feitas contagens diárias das covas em que nasceram plantas. Dos dados assim obtidos concluiu-se que, aplicados isoladamente, nos sulcos ou nas covas, o superfosfato e a farinha de ossos não prejudicaram o "stand". Entretanto, as aplicações isoladas de Renania-fosfato, assim como as adubações em que ao fósforo, sob qualquer forma, se adicionou cloreto de potássio, e sobretudo as que, além dêsses adubos, também tiveram salitre, reduziram fortemente o "stand" quando aplicadas nas covas; empregadas nos sulcos, prejudicaram muito menos. Além de reduzir o "stand", o salitre e o cloreto de potássio retardaram a emergência das plantas. Em regra, os danos cresceram com a concentração de adubos em tôrno das sementes, que foi muito maior nas covas. O período imediato ao plantio foi bastante chuvoso, concorrendo de um modo geral para diminuir os prejuízos. Com tempo sêco ou pouco chuvoso após o plantio, como acontece com freqüência, por certo a aplicação nos sulcos também teria sddo altamente prejudicial. Daí a conclusão de que certos adubos não devem ser aplicados pela maneira usual, como nos ensaios, e que, para avaliar o efeito dêsses adubos sôbre a produção do algodoeiro, se devem usar métodos outros que não os da aplicação nas covas ou nos sulcos de plantio.

Some Effects of Isopropyl N-(3-Chlorophenyl) Carbamate and an Alkanolamine Salt of Dinitro Ortho Secondary Butyl Phenol on Germinating Cotton Seeds

Some Effects of Isopropyl N-(3-Chlorophenyl) Carbamate and an Alkanolamine Salt of Dinitro Ortho Secondary Butyl Phenol on Germinating Cotton Seeds

Factors that Influence Life and Germination of Cotton SeeD

Factors that Influence Life and Germination of Cotton SeeD