The response of plant species used in agriculture and horticulture to viroid infections

The reactions of the viroids causing cucumber pale fruit (CPFV), chrysanthemum stunt (CSV) and citrus exocortis (CEV) in different plant species and varieties used in agriculture and horticulture were studied. These viroids caused identical symptoms on tomato and potato. The reactions of chrysanthemum Mistletoe to CPFV or CSV were identical, but CEV-infected plants reacted quite differently. CPFV and CEV caused the same type of symptoms on cucumber plants but symptoms of CEV were always weaker.Ten of the tested horticultural crop species appeared to be susceptible to CPFV, of which eight produced symptoms. In the Netherlands, however, CPFV is only described as pathogen on cucumber plants grown in glasshouses. Ten species were susceptible to CSV of which three produced symptoms. In the Netherlands CSV only occurs in chrysanthemum. Nine of the tested crops proved to be susceptible to CEV and seven were sensitive to this viroid which occurs in citric crops of (sub)tropical climate zones.Our results show that the viroids studies form potential pathogens for other crops than cucumber and chrysanthemum which are now affected by two of them.Samenvatting Het viroïde dat de bleke-vruchtenziekte bij komkommer veroorzaakt (CPFV), chrysanthemum stunt viroïde (CSV) en citrus exocortis viroïde (CEV) produceren symptomen op tomaat en aardappel, die niet van elkaar zijn te onderscheiden. De reactie van chrysant Mistletoe op CPFV of CSV is identiek, maar na infectie met CEV reageren de planten volkomen anders. Komkommers ontwikkelen dezelfde symptomen na een besmetting met CPFV en CEV, hoewel laatstgenoemd agens altijd een zwakker ziektebeeld oproept.Tomaat, aardappel, aubergine, chrysant, komkommer, augurk, meloen enBenincasa bleken gevoelig te zijn en paprika en petunia vatbaar voor CPFV, terwijl in Nederland alleen van komkommergewassen bekend is, dat ze aangetast worden door dit pathogeen.Tomaat, aardappel en chrysant waren ook gevoelig voor CSV, vatbaar voor dit viroïde waren paprika, petunia,Nicandra, andijvie, komkommer, augurk enBenincasa cerifera. In ons land kennen we stunt alleen in de chrysantenteelt. Negen gewassen bleken vatbaar te zijn voor CEV, en zeven waren gevoelig voor dit viroïde, dat alleen in (sub)tropische klimaatzones voorkomt.Vierentwintig cultuurgewassen bleken onvatbaar te zijn voor alle drie viroïden. De resultaten van dit onderzoek wijzen er op dat CPFV, CSV en CEV nauw verwant zijn, maar niet identiek.     

水稻淡绿叶突变体HM133的遗传分析与基因定位

EMS诱导籼稻品种IR64获得淡绿叶突变体HM133。与野生型IR64相比,HM133播种后的第6周和第15周的光合色素含量以及抽穗期的净光合速率显著降低,气孔导度则明显上升;此外,突变体株高、每穗实粒数和结实率等农艺性状也较野生型显著下降。叶绿体超微结构分析表明,分蘖期HM133类囊体基粒片层形状不规则,堆叠凌乱、排列疏松。遗传分析表明HM133淡绿叶性状受单隐性核基因控制。通过分子标记将该基因定位于第3染色体长臂RM143和RM3684之间。该区间内包含编码镁螯合酶D亚基的基因OsCHLD。序列分析表明HM133中该基因第10外显子上有一个从G突变为A的单碱基变异,导致编码的氨基酸由精氨酸变成谷氨酸,推测OsCHLD基因即为控制HM133淡绿叶表型的候选基因。     

A New Species of Mugilicola Parasitic on South African Elvers (Copepoda,Therodamasidae)

A new species of parasitic copepod belonging to the genus Mugilicola Tripathi, I960 (CYCLOPOIDA: THERODAMASIDAE) is described. The copepods were embedded in the buccal cavity of elvers of Anguilla mossambica caught in South African rivers.     

Pale and Normal Turkey Breast Enhancement Through the Utilization of Turkey Collagen in a Chunked and Formed Turkey Breast Roll

Six trials of 4 treatments (pale, pale + 1.5% collagen, normal, and normal + 1.5% collagen) were utilized to test the effects of raw material and turkey collagen inclusion on the quality of deli turkey breast. The raw material was chunked and formed to increase surface area for collagen interactions and to allow for thorough mixing of pale and normal raw material into the product. Inclusion of collagen improved product texture through increasing the protein's ability to bind with each other in pale meat and was effective in decreasing cook and purge loss in both pale and normal treatments. Furthermore, purge loss was similar for the pale treatment with collagen and the normal treatment without collagen. Collagen inclusion did not affect color, but normal treatments were both darker and redder than pale treatments. Turkey collagen is effective in increasing water-holding capacity and improving texture when either pale or normal raw material is incorporated into the product. Therefore, turkey collagen demonstrates the potential to add value to turkey breast deli products.     

Identification and Fine Mapping of a Gene Related to Pale Green Leaf Phenotype near the Centromere Region in Rice （Oryza sativa）

A thermo-insensitive pale green leaf mutant (pgl2) was isolated from T-DNA inserted transgenic lines of rice (Oryza sativa L. subsp. japonica cv. Nipponbare). Genetic analysis indicated that the phenotype was caused by a recessive mutation in a single nuclear-encoded gene. To map the PGL2 gene, an F2 population was constructed by crossing the mutant with Longtefu (Oryza sativa L. subsp. indica). The PGL2 locus was roughly linked to SSR marker RM331 on chromosome 8. To finely map the gene, 14 new InDel markers were developed around the marker, and PGL2 was further mapped to a 2.37 Mb centromeric region. Analysis on chlorophyll contents of leaves showed that there was no obvious difference between the mutant and the wild type in total chlorophyll (Chl) content, while the ratio of Chl a / Chl b in the mutant was only about 1, which was distinctly lower than that in the wild type, suggesting that the PGL2 gene was related to the conversion between Chl a and Chl b. Moreover, the method of primer design around the centromeric region was discussed, which would provide insight into fine mapping of the functional genes in plant centromeres.