The relationship between fruit size and cell division and enlargement in cultivated and wild persimmons

Summary

To determine the anatomical basis for differences in fruit size in Japanese persimmon (Diospyros kaki Thunb.), the number and sizes of parenchymal cells were measured in four astringent cultivars and in wild D. lotus over a single season in Japan. Fruit weight at harvest correlated with the final number of parenchymal cells (r = 0.95*) and their size (r = 0.92*). There was also a correlation between fruit diameter and the number of cell layers at full bloom (r = 0.93*), which increased 1.7 – 1.9-fold during fruit development.The duration of cell division and the sizes of the cells at full bloom were similar among the cultivars, whereas mean parenchymal cell lengths increased by 7.7-, 6.7-, 5.4-, 5.0- and 3.8-fold from full bloom to harvest in ‘Otanenashi’ (average fruit diameter = 96 mm), ‘Hiratanenashi’ (77 mm), ‘Saijo’ (54 mm), ‘Tsurunoko’ (44 mm), and D. lotus (20 mm), respectively. The final size of tannin cells was larger in ‘Otanenashi’ and ‘Hiratanenashi’ than in the other cultivars, including the wild species.These results indicate that the size of fruit at harvest was determined by the number of cells at full bloom, and their expansion during fruit development.     

Genetic diversity within and between sulfonylurea‐resistant and susceptible populations of Schoenoplectus juncoides in Japan

To reveal the effects of herbicide selection on genetic diversity in the outcrossing weed species Schoenoplectus juncoides, six sulfonylurea‐resistant (SU‐R) and eight sulfonylurea‐susceptible (SU‐S) populations were analysed using 40 polymorphic inter‐simple sequence repeat loci. The plants were collected from three widely separated regions: the Tohoku, Kanto and Kyushu districts of Japan. Genetic diversity values (Nei's gene diversity, h) within each SU‐S population ranged from h = 0.125 to h = 0.235. The average genetic diversity within the SU‐S populations was H_S = 0.161, and the total genetic diversity was H_T = 0.271. Although the H_S of the SU‐R populations (0.051) was lower than that of the SU‐S populations, the H_T of the SU‐R populations (0.202) was comparable with that of the SU‐S populations. Most of the genetic variation was found within the region for both the SU‐S and SU‐R populations (88% of the genetic variation respectively). Two of the SU‐R populations showed relatively high genetic diversity (h = 0.117 and 0.161), which were comparable with those of the SU‐S populations. In contrast, the genetic diversity within four SU‐R populations was much lower (from h = 0 to 0.018) than in the SU‐S populations. The results suggest that selection by sulfonylurea herbicides has decreased genetic diversity within some SU‐R populations of S. juncoides. The different level of genetic diversity in the SU‐R populations is most likely due to different levels of inbreeding in the populations.     

Intramammary application of ozone therapy to acute clinical mastitis in dairy cows

The infusion of ozone into the inflamed quarter of cows with clinical mastitis was performed and the efficacy of ozone therapy was evaluated. Ozone was infused into the inflamed quarter via a teat canal using ozone gas generating equipment. Nineteen Holstein cows with acute clinical mastitis were divided into two groups: 15 cows treated with ozone therapy, and 4 cows treated with antibiotic therapy. Systemic and local clinical signs, California Mastitis Test scores, the mastitis causing pathogens, electronic conductivity of milk, and somatic cell counts in milk from ozone- and antibiotic-treated quarters, were compared between the groups. Sixty percent (9/15) of cows with acute clinical mastitis treated with ozone therapy, did not require any antibiotics for recovery. This newly developed ozone therapy method was proven to be effective, safe, and cost effective, and carries no risk of drug residues in milk.     

Notoedric mange in two free-ranging North American racoons (Procyon lotor) in Japan

Mange was diagnosed in two North American racoons (Procyon lotor) at Kamakura City in Kanagawa Prefecture, Japan. The mites were identified morphologically as Notoedres cati. Mite infestation affected the skin over the extremities and tail, and was characterized by moderate alopecia and erythematous dermatosis. Histopathologically, the affected skin showed marked epidermal hyperplasia and mites located within the parakeratotic stratum corneum. A slight dermal inflammatory response consisting principally of mononuclear cells was observed. N. cati mites were demonstrated in their tunnels using scanning electron microscopy (SEM). This is the first report of notoedric mange in racoons.     

Mirex residues in wildlife and soils, Hawaiian pineapple-growing areas--1972-74.

A monitoring program was conducted in the pineapple-growing areas of Hawaii from 1972 to 1974 to survey mirex residues in sediments, soils, and aquatic and terrestrial wildlife. Residues in pineapple field soils ranged from 3 to 18 ppb 9 months after mirex had been applied. No residues were found in the sediments. Only 8 fish of 110 aquatic animals sampled contained mirex; these levels were low and ranged from 3 to 7 ppb. Mirex residues in birds ranged from undetectable to 10 ppm; residues in rodents were quite variable, but in terms of the geometric mean, the amounts in the Polynesian rat decreased with time from 1,270 to 56 ppb. Similarly, values for the roof rat ranged from 666 to 17 ppb. The geometric mean for residues in mongooses decreased from 2,200 ppb immediately after application to 238 ppb 39 weeks later. Aerial application of mirex to the pineapple fields did not contaminate the marine environment of Hawaii and no evidence of mirex residue buildup in the aquatic food chain was apparent. Mirex accumulation in terrestrial biota was temporary; there was no definitive indication of permanent accumulation in the wildlife of the areas studied.