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- Author or Editor: R.W. Breidenbach x
- Journal of the American Society for Horticultural Science x
Isothermal microcalorimetric measurements of metabolic heat rates of `Kerman' pistachio (Pistacia vera L.) individual inflorescence buds, current-year and 1-year-old shoots were used to investigate the roles of current and reserve photosynthates in the abscission of inflorescence buds. In the early stages of development metabolic heat rates of individual inflorescence buds were two and three times those of individual current-year and 1-year-old shoots respectively. Individual shoot organs (1-year-old shoots, current-year shoots, and inflorescence buds) sampled from “on” trees had higher metabolic heat rates than similar individual organs sampled from “off” trees. Artificial shading of pistachio trees for 14 days in early June depressed metabolic heat rates of individual inflorescence buds within 24 h, but there was a delay of 4 days before the decline in metabolic heat rates of individual current-year and 1-year-old shoots. This suggests that metabolic heat rates of individual inflorescence buds apparently depended on currently fixed photosynthates.
Abstract
The mode of inheritance of carboxylation efficiency (CE) of tomato (Lycopersicon esculentum Mill.) was studied using parents, F1, BCP1, BCP2, and F2 progeny from the crosses Ottawa 67 (067) × VF 145-7879 (7879) and 067 × LA959. The inheritance of chlorophyll content was studied with the cross 067 × LA959. The difference in CE between 067 and 7879 is controlled by a single gene with high CE apparently conditioned by the high pigment (hp) gene from 067. The differences in CE and chlorophyll content between 067 and LA959 are under digenic control. The differences appear to be controlled by hp from 067 and lurida (lur) from LA959. A causal relationship between chlorophyll content and CE may not exist, but the evidence presented indicates the two characteristics are closely related.
Abstract
The relative growth rates for tomato (Lycopersicon esculentum Mill.) genotypes differing in carboxylation efficiency (CE) were similar. Manapal (dg), which had a high CE, had a more rapid vegetative phase growth rate and LA 1098 (low CE) was slower growing. Specific leaf dry weight was greater in high CE genotypes indicating that it may be a useful selection criterion. Leaf thickness was greater in the high CE genotypes (Manapal (dg) and 067) than in the intermediate CE cultivars. Manapal (dg) and 067 (high CE) has much greater percent air space in the palisade tissue and much longer palisade cells than 7879 and VF 36 (intermediate CE). Conversely the number of palisade cells cm−2 was much less in the high CE genotypes. These results indicate that differences in gaseous diffusion potential may in part account for genotypic differences in CE. Differences in CE at 21 and 2% O2 indicated that genotypic differences for photorespiration rate was not an important contributor to the variation in CE.