Honeybees foraging response in genetically diversified opium poppy.

Studies were carried out on honeybees foraging on plant flowers. Results showed significantly higher foraging response of honeybees (Apis mellifera) in genetically divergent narcotic plant opium poppy (Papaver somniferum). Of the 18 mutants and two locally adapted cultivars of diverse genotypes screened, eight revealed significantly greater foraging response manifesting honeybee's preference towards specific plant morphotypes. The number of flower bloom did not correspond to number of foraging bees in both mutant and cultivar plant types of opium poppy. The genotype specific foraging response of honeybees could be attributed to physico-chemical properties of opium poppy flowers. This could have implications for the development of opium alkaloid fortified honeys for novel pharmaceuticals and isolation of natural spray compounds to attract honeybee pollinators for promoting crossing and sustainable hybridity in crops.

Comparative QSAR study of phenol derivatives with the help of density functional theory.

Quantum chemical reactivity descriptors based QSAR study of 50 phenol derivatives is presented in this paper. Four different methods have been employed to certify the reliability of QSAR study. The molecular weight, hardness, chemical potential, total energy, and electrophilicity index provide valuable information and have a significant role in the assessment of the toxicity of phenols. The first model has been drawn up with the help of AM1 calculations and in this model the correlation coefficient r2 is 0.88 and the cross-validation coefficient r(cv)2 is 0.78. Second and third models have been designed with the PM3 and PM5 calculations, respectively. The values of correlation coefficient r2 and cross-validation coefficient r(cv)2 in the second case are 0.85 and .070, while in the third case they are 0.85 and 0.71. Finally, the DFT calculations have been made for the same series of compounds by using a B88-PW91 GGA energy functional with the DZVP basis set. The DFT models have a higher predictive power than AM1, PM3, and PM5 methods, and the reliability of this model is clear from its correlation coefficient r2 0.91 and cross-validation coefficient r(cv)2 0.88. This study is also helpful in determining the effect of any particular phenol derivative of this series over Tetrahymena pyriformis.

Semiempirical QSAR study and ligand receptor interaction of estrogens.

Softness values E(n)+/+ of estrogen derivatives and softness values E(m)+/+ of receptor lysine, histidine, tyrosine and cysteine have been evaluated by Klopman equation. The required parameters for the solution of Klopman equation have been calculated with the help of PM3 method. The difference deltaE(nm)+/+ between E(n)+/+ and E(m)+/+ has been derived for QSAR study. The estrogen derivatives have been divided into four different sets on the basis of their structural similarities, and their biological activity taken from literature in terms of relative binding affinity (RBA). The QSAR study shows that, deltaE(nm)+/+ values provide good relationship with biological activity.

DFT-based QSAR study of testosterone and its derivatives.

QSAR study of derivatives of testosterone has been made with the help of quantum mechanical parameters such as Absolute Hardness (eta) and Electronegativity (chi). These two parameters have been derived with the help of density functional theory. The 3-D modeling and geometry optimization of all the compounds have been done with the help of PCMODEL software and semiempirical PM3 calculations performed with the help of WinMOPAC-7.21 software. The absolute hardness provides valuable information due to maximum hardness principle and used in development of QSAR. The information provided by electronegativity is not as clear as in case of absolute hardness.

Heterosis for chiasma frequency and quantitative traits in common beans (Phaseolus vulgaris L.).

Ten genotypes, including inbreds, hybrids, and advanced populations, were examined in order to elucidate the relationship between position and frequency distribution of chiasmata and quantitative traits, including yield heterosis in common beans. The hybrid and advanced population groups were determined to possess 83% and 54% increased chiasma frequency, respectively in contrast to inbred lines. The increase in chiasma frequency of these populations was further manifested in a high number of interstitial chiasmata. The regular and superior chromosome behaviour of the hybrids was found to be positively associated with quantitative measures on bean yield, harvest index and bean yield efficiency. The results were discussed from the point of view that: a) increased interstitial chiasmata may provide an effective mechanism for maintaining genetic diversity and heterosis in hybrid populations; and b) heterosis for chiasma frequency and quantitative traits may be due to dispersed genes on the chromosomes having combined intra-and interallelic interactions. The data provide evidence for the existence of positive associations between interstitially localized chiasmata with its recombination potential and regular chromosome behaviour to bean yield heterosis. The role of enhanced interstitial chiasmata to promote higher levels of genetic variation and heterozygous advantage is discussed.

Correlation between chiasma frequency and quantitative traits in upland cotton (Gossypium hirsutum L.).

Four locally adapted and high yielding cultivars of upland cotton were examined in order to elucidate the relationship between total chiasma frequency and quantitative traits, including yield and fiber properties. Total chiasma frequency per nucleus was found to correlate positively with boll number (r = 0.4041), seed cotton yield (r = 0.6003), seed index (r = 0.4624), lint yield (r = 0.7325), and lint index (r = 0.9534). The data are discussed from the point of view that the heterozygosity caused by increased chiasma frequency in inbreeding cotton cultivars is an important compensating mechanism for enhancing effective recombination and genetic variability.

High efficiency, heterosis, and homeostasis in mitochondria of wheat.

Mitochondria of a wheat hybrid 31MS x 28 when assayed polarographically exceeded mitochondria of parents of the hybrid in ADP:O ratios and in respiratory control when they utilized alpha-ketoglutarate, malate, and succinate. The ADP:O ratios of the hybrid mitochondria for the three substrates were 5.8 +/- 0.2, 3.8 +/- 0.15, and 3.4 +/- 0.2, respectively. High P:O ratios were also observed in manometric assays. Mixtures of parental mitochondria exceeded averages of the parents, i.e., they exhibited complementation and approached activities of hybrid mitochondria. Complementation was observed only with NAD-linked substrates. Dinitrophenol uncoupled all mitochondria, but uncoupling was smallest in hybrid mitochondria. Hybrid mitochondria had the greatest ATPase activity. Mixtures exhibited complementation in ATPase activity. ATPase activity was stimulated least in hybrid mitochondria and in parental mixtures. The results were discussed from the point of view that the high P:) ratios gave us direct evidence that heterosis is indeed characterized by high efficiency. It is also pointed out that because of consistent repeatability and their specificity to hybrids, P:O ratios studied in rapidly isolated mitochondria of hybrids may give us revealing information on supramaximal efficiency of oxidative phosphorylation.

On methods of isolation of active, tightly coupled mitochondria of wheat seedlings.

Tightly coupled mitochondria can be isolated from wheat seedlings 1) if young seedlings are used, 2) if the grinding medium is buffered and contains bovine serum albumin (BSA), 3) if the isolation procedure, including centrifugation is 10 to 11 minutes long. Mitochondria isolated in this manner oxidize alpha-ketoglutarate, malate and NADH. Respiratory control (R.C.) values are around 6, 3, and 10, respectively. ADP:O values with those substrates are 4.0, 2.9, and 1.7, respectively. Mitochondria are stable for 3 hours. It is suggested that the technique may be used for preparation of mitochondria for comparative studies since activities of these mitochondria are highly reproducible.