Of tubers

The effect of endogenous PL3 (A) and externally applied E. carotovora enzymes (B) on the cell viability of tuber tissue disks from PL-inactive (I) and PL-active (II) plant lines. 

Maceration of tuber tissue from pB33-PL3 transformants with Ec-Bacteria (lxlO cfti/ml). 

Other treatments have similar effects to those of early planting and include priming of true seed, presprouting of tubers as in potatoes and the use of transplants. Generally, there is some flexibility in the use of such treatments in annual crops but it may be limited by local agro-meteorological conditions or the need to deliver a crop to the market at a predetermined time. Of course, the limitations are even greater in perennial crops. 

Rolfe, M., McLeod, L. E., Pratt, P. F., and Proud, C. G. (2005). Activation of protein synthesis in cardiomyocytes by the hypertrophic agent phenylephrine requires the activation of ERK and involves phosphorylation of tuberous sclerosis complex 2 (TSC2). Biochem. J. 388, 973-984. 

From a study of 6 varieties of tubers from different regions of Asia and grown at two locations (Western Australia and Malaysia), Kortt and Caldwell (70) concluded that,... 

Proteins and Proteinase Isolation/Assay. Pieces of tuber were... 

Protein contents of tuber extracts were determined by the method of Lowry et al. (15j using bovine serum albumin as the... 

Numerous other chemicals have been tested on nut grass. TCA delays the germination of tubers but does not materially reduce the stand. A combination of TCA and 2,4-D was superior to either chemical in Brazil (40). Methyl bromide has proved excellent for the control of nut grass in the United States (23) and on a small scale in Puerto Rico. Unfortunately, it is expensive and difficult to apply. CMU kills nut grass, especially if applications are alternated with plowing, but leaves the soil unusable for crops for an extended period and is too expensive for large scale application (28). 

The dose required to inhibit sprouting of onions, shallots, and garlics is 0.03-0.12 kGy. For good sprout control of tubers such as potatoes and yams, somewhat higher doses, 0.08-0.14 kGy, are required. Because of decreased wound-healing ability after irradiation, doses in excess of 0.15-0.2 kGy may induce increased microbial rot in storage [24]. 

An important factor determining the efficacy of radiation treatment of tubers and bulbs is the time delay between harvest and irradiation. The sprout inhibition is most pronounced if the irradiation of tubers and bulbs is applied shortly after harvest, when they are still in their dormancy stage. However, the dormancy period may vary among cultivars and cropping season, and is also dependent on the postharvest storage temperature. 

Many genetic studies in potato have focused on disease resistance. A summary of disease resistance genes and quantitative trait loci in potato has recently been published (Celebi-Toprak et al., 2005b). In addition, major quantitative trait loci have been identified for tuber dormancy (chromosome II), tuber eye depth (chromosome X), flesh color (chromosome IV), tuber shape (chromosome II) and uniformity of tuber shape (chromosome III) (Sliwka et al., 2008). 

Blenkinsop, R. W., Copp, L. J., Yada, R. Y, Marangoni, A. G. (2002). Changes in eompositional parameters of tubers of potato (Solanum tuberosum) during low-temperature storage and their relationship to ehip proeessing quality. Journal of Agricultural and Food Chemistry, 50,4545 553. 

Gebhardt, C., Menendez, C., Chen, X., Schafer-Pregl, R., Salamini, F. (2005). Genomic approaches for the improvement of tuber quality traits in potato. Acta Horticulturae, 684, 85. 

Sliwka, J., Wasilewicz-Flis, I., Jakuczun, H., Gebhardt, C. (2008). Tagging quantitative trait loci for dormancy, tuber shape, regularity of tuber shape, eye depth and flesh colour in diploid potato originated from six Solanum species. Plant Breeding, 127, 49-55. 

Yerk, G. L., Peloquin, S. J. (1989). Evaluation of tuber traits of 10,2x(2EBN) wild species through hybrid x wild species hybrids. American Potato Journal, 66, 731-739. 

Hoover, R. (2001). Composition, molecular structure, and physicochemical properties of tuber and root starches a review. Carbohydr. Polym., 45, 253-267. 

Figure 5.5 Distribution of mineral elements within potato tubers. Data show longitudinal profiles of elements from the distal (Segment 1) to the stem end (Segment 5) of tubers from Stirling plants (N. Subramanian, G. Ramsay, M. R. Broadley and P.J. White, unpublished data).

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