Ecologically and economically important fleshy edible fruits have evolved from dry fruit numerous times during angiosperm diversification. However, the molecular mechanisms that underlie these shifts are unknown. In the Solanaceae there has been a major shift to fleshy fruits in the subfamily Solanoideae. Evidence suggests that an ortholog of FRUITFULL ( FUL ), a transcription factor that regulates cell proliferation and limits the dehiscence zone in the silique of Arabidopsis , plays a similar role in dry-fruited Solanaceae. However, studies have shown that FUL orthologs have taken on new functions in fleshy fruit development, including regulating elements of tomato ripening such as pigment accumulation. FUL belongs to the core eudicot euFUL clade of the angiosperm AP1 / FUL gene lineage. The euFUL genes fall into two paralogous clades, euFULI and euFULII . While most core eudicots have one gene in each clade, Solanaceae have two: FUL1 and FUL2 in the former, and MBP10 and MBP20 in the latter. We characterized the evolution of the euFUL genes to identify changes that might be correlated with the origin of fleshy fruit in Solanaceae. Our analyses revealed that the Solanaceae FUL1 and FUL2 clades probably originated through an early whole genome multiplication event. By contrast, the data suggest that the MBP10 and MBP20 clades are the result of a later tandem duplication event. MBP10 is expressed at weak to moderate levels, and its atypical short first intron lacks putative transcription factor binding sites, indicating possible pseudogenization. Consistent with this, our analyses show that MBP10 is evolving at a faster rate compared to MBP20. Our analyses found that Solanaceae euFUL gene duplications, evolutionary rates, and changes in protein residues and expression patterns are not correlated with the shift in fruit type. This suggests deeper analyses are needed to identify the mechanism underlying the change in FUL ortholog function.

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The evolutionary transition from outcross-fertilization to self-fertilization is one of the most common in angiosperms and is often associated with a parallel shift in floral morphological and developmental traits, such as reduced flower size and pollen to ovule ratios, known as the ‘selfing syndrome’. How these convergent phenotypes arise, the extent to which they are shaped by selection, and the nature of their underlying genetic basis are unsettled questions in evolutionary biology. The genus Collinsia (Plantaginaceae) includes seven independent transitions from outcrossing or mixed mating to high selfing rates accompanied by selfing syndrome traits. Accordingly, Collinsia represents an ideal system for investigating this parallelism, but requires genomic resource development. We present a high quality de novo genome assembly for the highly selfing species C. rattanii. To begin addressing the basis of selfing syndrome developmental shifts, we evaluate and contrast patterns of gene expression from floral transcriptomes across three stages of bud development for C. rattanii and its outcrossing sister species C. linearis. Relative to C. linearis, total gene expression is less variable among individuals and bud stages in C. rattanii. In addition, there is a common pattern among differentially expressed genes: lower expression levels that are more constant across bud development in C. rattanii relative to C. linearis. Transcriptional regulation of enzymes involved in pollen formation specifically in early bud development may influence floral traits that distinguish selfing and outcrossing Collinsia species through pleiotropic functions. Future work will include additional Collinsia outcrossing-selfing species pairs to identify genomic signatures of parallel evolution.

Translocations of the short arm of rye (Secale cereale L.) chromosome 1 (1RS) in wheat (Triticum aestivum L. cv. Pavon 76) are known to increase root biomass. Such an increase enhances water and nutrient uptake and may improve grain yield. Two greenhouse experiments and a field experiment were carried out at the University of California, Riverside, in 2012 and 2013 under well-watered and terminal drought treatments to evaluate phenotypic characters associated with varying dosages of 1RS, including grain yield. The genotypes used were cultivar Pavon 76 (R 0 ), Pavon 76/Pavon1RS.1AL (F 1 hybrid) with a single dosage of 1RS (R 1 A), Pavon 1RS.1AL with two dosages of 1RS (R 2 A), Pavon 1RS.1DL (R 2 D) also with two dosages of 1RS and Pavon 1RS.1AL-1RS.1DL (R 4 AD) with four dosages of 1RS. There was a significant positive correlation between number of dosages of 1RS and root biomass. However, no correlation was found between root biomass and grain yield per plant. Drought in the field experiment reduced grain yield significantly. Under well-watered field conditions, grain yield of R 2 A (215.9 g plant À1 ) was significantly greater than those of R 2 D (191.8 g plant À1 ) and R 4 AD (161.7 g plant À1 ). Also, grain yield of R 4 AD was significantly less than those of F 1 , Pavon 76 and R 2 D under well-watered conditions. Under drought field conditions, no significant differences were found among the genotypes for grain yield was found between F 1 (14.7 g plant À1 ) and R 4 AD (12.4 g plant À1 ). Harvest index was significantly greater in well-watered (44.2 %) than in drought (34.6 %) field conditions. On average, genotypes F 1 (42.3 %) and R 2 A (40.6 %) had higher harvest index than R 2 D (38.3 %) and R 4 AD (35.5 %) in the field. Also, Pavon 76 (40.2) and R 2 D (38.3) had higher harvest index than R 4 AD. Drought tolerance was lowest for R 4 AD due to its relatively lower grain yield potential. In general, Pavon 1RS.1AL carrying two dosages of 1RS showed higher grain yield under wet treatments. Pavon 1RS.1AL-1RS.1DL carrying four dosages of 1RS produced the largest shoot and root biomasses, but the least grain yield.

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