Corncob flower, Magnolia mixteca (M. sect. Macrophylla, Magnoliaceae) a new species endemic to the Alto Balsas Basin (Baja Mixteca), in the Pacific slopes of Oaxaca, Mexico

We describe and illustrate Magnolia mixteca, a new species of Magnolia sect. Macrophylla from the Alto Balsas Basin in Oaxaca, Mexico, providing information about its ecology, biogeography and conservation status. Magnolia mixteca differs from M. nuevoleonensis in having larger flowers, longer petals, a yellow petal-blotch, a tan-sand coloured ovary and more numerous stamens and carpels. In addition, we provide a distribution map and key to species of sect. Macrophylla. The relict distribution of this species allows us to consider it endangered (E).

Characterization and categorization of Indian mustard genotypes for agro-morphological traits

A total of sixty genotypes and germplasm lines were evaluated and characterized for 14 quantitative and 8 qualitative traits in Brassica juncea. Observations were recorded on the basis of scores given in the DUS descriptor. Majority of accessions were very late in maturity and medium in flowering. No variability was observed for leaf length and leaf width. On the basis of branches, most of the genotypes were classified under intermediate category. Long main shoot length (31), medium number of siliquae on main shoot (46), medium density on main shoot (52), short siliqua length (51), very tall plant height (38), few numbers of seeds per siliqua (33), medium 1000-seed weight (38), medium seed yield per plant (32) and low oil content (40) were observed in most of the genotypes. For qualitative traits, most of the genotype showed dark green leaf color, sparse hairs, dentation of leaf margin lyrate type, open leaf growth habit, yellow petal color, semi-appressedsiliqua angle with main shoot and intermediate siliqua surface texture. Wide (Yellow, Dull grey, Reddish brown, Brown and Black) diversity has been observed for seed color.

Elucidation of the Roles of Blackcurrant reversion virus and Phytoplasma in the Etiology of Full Blossom Disease in Currants

To determine the roles of phytoplasmas and Blackcurrant reversion virus (BRV) in the etiology of full blossom disease (FBD), we conducted graft and dodder transmission experiments. Scions from FBD-affected Ribes rubrum were grafted onto red currants, white currants, and black currants. Red and white cultivars revealed symptoms of FBD, whereas blackcurrant displayed symptoms of BRV. No differences in symptoms were observed between plants infected with BRV only and those infected with BRV and phytoplasma. Aster yellows phytoplasma subgroup 16SrI-C was transferred from FBD-infected red currants to periwinkle, where symptoms of green and yellow petal were observed. Back-transmission of phytoplasma to currant seedlings of red and black currant was not successful. Scions of periwinkle infected with aster yellows phytoplasmas of subgroup 16SrI-C and 16SrI-B, which were bottle-, bark-, and approach-grafted onto seedlings of red and black currant, resulted in positive but symptomless transmission of phytoplasma to red currant. We conclude that FBD symptoms are induced by BRV rather than by phytoplasma, which was originally described as the causal agent of FBD.