Relative Embryo Growth Rates in the Annual Cicer L. Species

Early embryo growth rates were studied in the nine annual speciesof Cicer L., namely, C. arietinum L., C. bijugum Rech., C. chorassanicum(Bge.) M. Pop., C. cuneatum Rich., C. echinospermum Dav., C.judaicum Boiss, C. pinnatifidum J. and S., C. reticulatum Lad.and C. yamashitae Kit. The number of embryo cells increasedexponentially with time and was log linear in all the species.Species differed in their mean cell doubling time (MCDT). Cicerechinospermum and C. yamashitae had, respectively, the longestand the shortest MCDT which ranged from 9.67 to 16.15 h forthe nine species. Failure of successful interspecific hybridizationbetween C. arietinum and the wild annual species was only partlyexplained by differences in MCDT of the parental species. Relativegenetic closeness still plays the major role in determiningsuccess of interspecific hybridization in Cicer. Chickpea, Cicer, embryo, interspecific hybridization, suspensor     

Alteration of the Pattern of Distribution of Photosynthetic Products in the Tomato by Manipulation of the Plant

To increase the proportion of photosynthates exported from tomatoleaves and to examine how far the subsequent distribution islinked with the activity of physiological sinks two types ofprocedures were used. In the first experiment the number ofsources of photosynthates was reduced by removing leaves orexcluding light from them and the growth of the fruit increasedby applying growth regulators. By this means a 30–50 percent increase in the export of radio-active photosynthates inthe first 24 h from a test leaf exposed to ¹⁴CO₂ was recorded.The enhanced activity of the sinks induced by growth regulatorsalthough increasing the amount of ¹⁴C material leaving a leafdid not increase the proportion of the exported fraction whichentered the fruit. In contrast a reduction in the number ofphotosynthetic sources increased both the absolute and relativeamounts entering the fruit from the treated leaf. In the second experiment grafts were made between potato andtomato in both directions. When the potato was the rootstockboth tomato and potato leaves exposed to ¹⁴CO₂ exported a higherproportion of the radioactive assimilates than when the tomatowas the rootstock. Movement was greater from scion to root-stockthan vice versa. The results are discussed in the context of fruit productionby the tomato and the extent to which yield of fruit is determinedby internal factors.     

Size-hierarchy in a year-class and "condition" of common minnow Esomus danricus (Ham.) in relation to various ecological factors operating in the pond environment

Investigations were made on the existence of size-hierarchy in specimens of Esomus danricus (Ham.) belonging to the same year-class, and the variations in condition factor of the different size-groups. Divergence in the growth rates of individual fish resulted in the development of size-hierarchy in the population. Marked changes seemed to occur in condition factor of the different size-groups. A multitude of factors operating simultaneously in the pond environment appeared to govern the condition factor of fish.     

Distinction of strains of bean common mosaic virus and blackeye cowpea mosaic virus using antibodies to N- and C- or N-terminal peptide domains of coat proteins

Earlier attempts to discriminate serologically strains NL1, NL3 and NY15 of bean common mosaic virus (BCMV) and strain W of blackeye cowpea mosaic virus (B1CMV) had been unsuccessful. Antibodies directed towards N- and C-, or N-terminal peptide regions of the coat proteins of the above strains enabled the distinction between B1CMV-W, BCMV-NY15 and BCMV-NL3 in electroblot immunoassay and in ELISA. The distinction was better with antibodies directed towards N-termini than with those to N- and C-termini. Strain NL1 of BCMV cross-reacted with both B1CMV-W and BCMV-NY15, but not with BCMV-NL3. Taxonomic implications of these findings are discussed.