Measuring the relative effect of factors affecting species distribution model predictions

1. Species distribution models are increasingly used to address conservation questions, so their predictive capacity requires careful evaluation. Previous studies have shown how individual factors used in model construction can affect prediction. Although some factors probably have negligible effects compared to others, their relative effects are largely unknown. 2. We introduce a general "virtual ecologist" framework to study the relative importance of factors involved in the construction of species distribution models. 3. We illustrate the framework by examining the relative importance of five key factors-a missing covariate, spatial autocorrelation due to a dispersal process in presences/absences, sample size, sampling design and modeling technique-in a real study framework based on plants in a mountain landscape at regional scale, and show that, for the parameter values considered here, most of the variation in prediction accuracy is due to sample size and modeling technique. Contrary to repeatedly reported concerns, spatial autocorrelation has only comparatively small effects. 4. This study shows the importance of using a nested statistical framework to evaluate the relative effects of factors that may affect species distribution models.

Arabidopsis Basic Helix-Loop-Helix Transcription Factors MYC2, MYC3, and MYC4 Regulate Glucosinolate Biosynthesis, Insect Performance, and Feeding Behavior.

Arabidopsis thaliana plants fend off insect attack by constitutive and inducible production of toxic metabolites, such as glucosinolates (GSs). A triple mutant lacking MYC2, MYC3, and MYC4, three basic helix-loop-helix transcription factors that are known to additively control jasmonate-related defense responses, was shown to have a highly reduced expression of GS biosynthesis genes. The myc2 myc3 myc4 (myc234) triple mutant was almost completely devoid of GS and was extremely susceptible to the generalist herbivore Spodoptera littoralis. On the contrary, the specialist Pieris brassicae was unaffected by the presence of GS and preferred to feed on wild-type plants. In addition, lack of GS in myc234 drastically modified S. littoralis feeding behavior. Surprisingly, the expression of MYB factors known to regulate GS biosynthesis genes was not altered in myc234, suggesting that MYC2/MYC3/MYC4 are necessary for direct transcriptional activation of GS biosynthesis genes. To support this, chromatin immunoprecipitation analysis showed that MYC2 binds directly to the promoter of several GS biosynthesis genes in vivo. Furthermore, yeast two-hybrid and pull-down experiments indicated that MYC2/MYC3/MYC4 interact directly with GS-related MYBs. This specific MYC-MYB interaction plays a crucial role in the regulation of defense secondary metabolite production and underlines the importance of GS in shaping plant interactions with adapted and nonadapted herbivores.

Agronomic characteristics of 'Prata-anã' and 'Maçã' bananas micropropagated

The experiment evaluated the agronomic characteristics of 'Prata-anã' and 'Maçã' banana plants, in the São Manuel region of São Paulo state. In the first crop cycle, the number of days from planting to inflorescence and from inflorescence to harvest; the number of shoots until the appearance of inflorescence and during the harvest period; active leaves number at inflorescence appearance and during the harvest period. Were evaluated yield parameters: like average weight of bunch, hand, rachis and fruit; average fruit number per hand and bunch; average fruit diameter and length. Incidences of plague diseases, as well as their severity were also evaluated. Delineation was totally at random, with 2 treatments, 15 replications and 5 useful plants per experimental plot. Both cultivars were characterized by values of descriptive average statistics and standard deviation, for characteristic interests. Number of days from planting to harvest was similar for both 'Prata-anã' and 'Maçã', 574 and 567 days respectively. Banana plants showed good phytosanitary quality throughout the whole cycle.

Evaluation of Xylella fastidiosa genetic diversity by fAFPL markers

The first phytopathogenic bacterium with its DNA entirely sequenced is being detected and isolated from different host plants in several geographic regions. Although it causes diseases in cultures of economic importance, such as citrus, coffee, and grapevine little is known about the genetic relationships among different strains. Actually, all strains are grouped as a single species, Xylella fastidiosa, despite colonizing different hosts, developing symptoms, and different physiological and microbiological observed conditions. The existence of genetic diversity among X. fastidiosa strains was detected by different methodological techniques, since cultural to molecular methods. However, little is know about the phylogenetic relationships developed by Brazilian strains obtained from coffee and citrus plants. In order to evaluate it, fAFLP markers were used to verify genetic diversity and phylogenetic relationships developed by Brazilian and strange strains. fAFLP is an efficient technique, with high reproducibility that is currently used for bacterial typing and classification. The obtained results showed that Brazilian strains present genetic diversity and that the strains from this study were grouped distinctly according host and geographical origin like citrus-coffee, temecula-grapevine-mulberry and plum-elm.

Occurrence and biology of Tolype innocens (Burmeister) on blueberry

Tolype innocens (Burmeister, 1878) is reported for the first time damaging blueberry (Vaccinium ashei) plants in Brazil having the caterpillars feeding on leaves and new shoots. T. innocens biology was studied on blueberry leaves in laboratory conditions and then a fertility life table was elaborated. Developmental time and viability of egg, larval and pupal stages and egg-adult period were 15.0 and 35.3, 33.3 and 84.5, 20.6 and 100, and 69.2 days and 45%, respectively. Average pupal weight was 0.840g for the females and 0.580g for the males. The sex ratio was 0.5. Pre-oviposition and oviposition time lasted 6.34 and 12.1 days, respectively. Mean fecundity was 251 eggs per female. Eggs were laid either individually or in masses. Longevity was 19.0 and 20.0 days for males and females, respectively. T. innocens population increased 47 times per generation, with a mean generation time of 77 days, and a finite rate of increase of 1.02. This data on biological parameters will be useful for establishing control strategies.