Genetic analysis of yield traits in Egyptian cotton crosses (Gossypium barbdense L.) under normal conditions.

To generate high-yielding cultivars with favorable fiber quality traits, cotton breeders can use information about combining ability and gene activity within a population to locate elite parents and potential F1 crosses. To this end, in the current study, twelve cotton parents (eight genotypes as female parents and four testers) and their F1 crosses obtained utilizing the linex tester mating design were evaluated for their general and specialized combining abilities (GCA and SCA, respectively) of yield traits. The findings showed that for all the investigated variables, variances owing to genotypes, parents, crosses, and parent vs cross showed extremely significant (P ≤ 0.01) differences. Additionally, throughout the course of two growing seasons, the mean squares for genotypes (parents and crosses) showed strong significance for all the variables under study. The greatest and most desired means for all the examined qualities were in the parent G.94, Pima S6, and tester G.86. The best crossings for the qualities examined were G.86 (G.89 × G.86), G.93 × Suvin, and G.86 × Suvin. The parents' Suvin, G89x G86 and TNB were shown to have the most desired general combining ability effects for seed cotton yield/plant, lint yield/plant, boll weight, number of bolls/plants, and lint index, while Suvin, G.96 and pima S6 were preferred for favored lint percentage. For seed cotton yield, lint percentage, boll weight, and number of bolls per plant per year, the cross-G.86 x (G.89 × G.86) displayed highly significant specific combining ability impacts. The crosses G.86 × Suvin, Kar x TNB, G.93 × Suvin, and G.93 × TNB for all the studied traits for each year and their combined were found to have highly significant positive heterotic effects relative to better parent, and they could be used in future cotton breeding programs for improving the studied traits.

Nitrogen fertilization coupled with iron foliar application improves the photosynthetic characteristics, photosynthetic nitrogen use efficiency, and the related enzymes of maize crops under different planting patterns.

Photosynthetic rate (Pn) and photosynthetic nitrogen use efficiency (PNUE) are the two important factors affecting the photosynthesis and nutrient utilization of plant leaves. However, the effect of N fertilization combined with foliar application of Fe on the Pn and PNUE of the maize crops under different planting patterns (i.e., monocropping and intercropping) is elusive. Therefore, this experiment was conducted to determine the effect of N fertilization combined with foliar application of Fe on the photosynthetic characteristics, PNUE, and the associated enzymes of the maize crops under different planting patterns. The results of this study showed that under intercropping, maize treated with N fertilizer combined with foliar application of Fe had not only significantly (p < 0.05) improved physio-agronomic indices but also higher chlorophyll content, better photosynthetic characteristics, and related leaf traits. In addition, the same crops under such treatments had increased photosynthetic enzyme activity (i.e., rubisco activity) and nitrogen metabolism enzymes activities, such as nitrate reductase (NR activity), nitrite reductase (NiR activity), and glutamate synthase (GOGAT activity). Consequently, intercropping enhanced the PNUE and soluble sugar content of the maize crops, thus increasing its yield compared with monocropping. Thus, these findings suggest that intercropping under optimal N fertilizer application combined with Fe foliation can improve the chlorophyll content and photosynthetic characteristics of maize crops by regulating the associated enzymatic activities. Consequently, this results in enhanced PNUE, which eventually leads to better growth and higher yield in the intercropping system. Thus, practicing intercropping under optimal nutrient management (i.e., N and Fe) could be crucial for better growth and yield, and efficient nitrogen use efficiency of maize crops.

Spectrophotometric evidence for the formation of short-lived hypomanganate(V) and manganate(VI) transient species during the oxidation of K-carrageenan by alkaline permanganate.

Spectrophotometric detection of the formation of short-lived hypomanganate(V), [KCAR-Mn(V)O43-], and manganate(VI), [KCAR-Mn(VI)O42-], intermediates has been confirmed through the oxidation of K-carrageenan (KCAR) by potassium permanganate in alkaline solutions of pH's >or= 12 using a conventional spectrophotometer. The short-lived transient species were characterized and a mechanism consistent with experimental observations is suggested.

Synthesis of some new azoles and azines and their condensed derivatives.

Ethyl (2,5-Dimethylphenyl) pyruvate (2) condensed with o-phenylenediamine, ethylenediamine, semicarbazide and thiosemicarbazide and gave quinoxaline derivative (3), dihydropyrazine derivative (9) and 1,2,4-triazine derivatives (10, 11) respectively. Compound (3) reacted with phosphorous pentasulphide, polyphosphoric acid, semicarbazide hydrochloride and phenylisothiocyanate yielded thienoquinoxaline derivative (4), furoquinoxaline derivative (5), semicarbazone derivative (6) and pyrrole derivative (15) respectively. Reaction of (2) with hydrazines and malononitrile afforded the arylpyrazole derivatives (12a, b) and pyrane derivative (13) respectively. Heterocyclization of compound (6) afforded thiadiazole and selenodiazole derivatives (7), (8).

Synthesis of some new pyrimidine and fused pyrimidine derivatives (Part 2).

6-Oxo-4(2-thienyl)-2-thioxo-1,3-dihydropyrimidine-5-carbonitrile (1) was synthesized and reacted with alkyl halides to give the S-alkyl compounds (2a,b), which reacted with phosphorous oxychloride to yield (3a,b). Reaction of 3a,b with phenyl-hydrazine, hydrazine hydrate, ammonia, acid hydrazides and thiourea leads to formation of the compounds (4a,b), the dihydrazino compound derivative (5), the amino compounds (7a,b), triazolopyrimidine derivatives (9a-d), and the mercapto compounds (10a,b), respectively. Treatment of (10a) with chloroacetone gave (11a), which condensed with benzaldehyde giving the tricyclic compound (12). Also (10b) reacted with ethyl chloroacetate followed by hydrolysis and cyclization yielded (14). Heating of (5) gave (6), which reacted with sodium nitrite and/or carbondisulphide and give (15) and (16), respectively.

Synthesis of some new pyrimidine and fused pyrimidine derivatives (Part I).

2-Hydroxy- and 2-Mercapto-3,4-dihydro-4-oxo-6-(furyl)-pyrimidine-5-carbonitriles (3a, b) were synthesized by two different routes. Methylation of 3a with methyl iodide gave the S-methyl derivative 4, which could also be prepared by two other different methods. The reaction of 4 with phosphorous oxychloride yielded the 4-chloro-pyrimidine derivative 6, which reacted with hydrazine hydrate, aroylhydr-azines, thiourea and phenylhydrazine to form the tetra-substituted pyrimidine derivative (8), the triazolopyrimidine derivatives (14a, b), the mercapto compound 7 and the pyrazolo[3,4-d]pyrimidine derivative 11, respectively. Compound 7 reacted with chloroacetone and gave 15 which reacted with aromatic aldehydes affording the tricyclic compounds (16a, b). Reaction of 8 with carbon disulphide and/or nitrous acid yielded the pyrazolo[3,4-d]-S-triazolo-[3,4-d]pyrimidine 13 and 12, respectively.

Kinetics and mechanism of permanganate oxidation of iota- and lambda-carrageenan polysaccharides as sulfated carbohydrates in acid perchlorate solutions.

The kinetics of oxidation of iota- and lambda-carrageenan as sulfated carbohydrates by permanganate ion in aqueous perchlorate solutions at a constant ionic strength of 2.0 mol dm(-3) have been investigated spectrophotometrically. The pseudo-first-order plots were found to be of inverted S-shape throughout the entire courses of reactions. The initial rates were found to be relatively slow in the early stages, followed by an increase in the oxidation rates over longer time periods. The experimental observations showed first-order dependences in permanganate and fractional first-order kinetics with respect to both carrageenans concentration for both the induction and autoacceleration periods. The results obtained at various hydrogen ion concentrations showed that the oxidation processes in these redox systems are acid-catalyzed throughout the two stages of oxidation reactions. The added salts lead to the prediction that Mn(III) is the reactive species throughout the autoacceleration periods. Kinetic evidence for the formation of 1:1 intermediate complexes was revealed. The kinetic parameters have been evaluated and tentative reaction mechanisms in good agreement with the kinetic results are discussed.

Further evidence for detection of short-lived transient hypomanganate(V) and manganate(VI) intermediates during oxidation of some sulfated polysaccharides by alkaline permanganate using conventional spectrophotometric techniques.

Spectrophotometric evidence for the formation of hypomanganate(V), [CAR-Mn(V)O43-], and manganate(VI), [CAR-Mn(VI)O42-], intermediate complexes has been confirmed during the oxidation of iota- and lambda-carrageenan-sulfated polysaccharides (CAR) by alkaline permanganate at pHs 12 using a conventional spectrophotometer. These short-lived intermediate complexes were identified and characterized. A reaction mechanism in good consistence with the experimental results is suggested.