Viridiana Silva Pérez

• Doctor of Philosophy
• Analaytical Scientist at Nourish Ingredients

This study aimed to identify the optimal flowering times to maximise yield of lentil in current growing regions and areas of potential expansion of this crop in Australia. We used the validated APSIM-lentil model and identified critical reproductive periods matching minimum risk of abiotic stresses and then applied an ideotype breeding approach cou...

Lentil breeding has produced genotypes with early maturity and greater yields. Breeding for better shoot and yield traits has indirectly selected smaller roots. Genotypes differed significantly in both shoot and root traits. Late maturing genotypes accumulated more shoot and root biomass. Root biomass had a negative impact on yield traits under...

Background Pulses are cultivated across a range of soil and climatic conditions that often have many abiotic constraints to production. Whilst water stress has been identified as the greatest constraint in Australian pulse cultivation, other limitations include heat, frost, nutrient deficiency, and a variety of soil physiochemical constraints. Seve...

Ideotype breeding is an essential approach for selection of desired combination of plant traits for testing in crop growth model for potential yield gain in specific environments and management practices. Here we parameterized plant traits for untested lentil cultivars for the APSIM-lentil model in phenology, biomass, and seed yield. We then tested...

Genetic progress in seed yield in lentils (Lens culinaris Medik) has increased by 1.1% per year in Australia over the past 27 years. Knowing which plant traits have changed through breeding during this time can give important insights as to how lentil yield has increased. This study aims to identify morphological and physiological traits that were...

Improvement of photosynthetic traits in crops to increase yield potential and crop resilience has recently become a major breeding target. Synthetic biology and genetic technologies offer unparalleled opportunities to create new genetics for photosynthetic traits driven by existing fundamental knowledge. However, large "gene bank" collections of ge...

Background The need for rapid in-field measurement of key traits contributing to yield over many thousands of genotypes is a major roadblock in crop breeding. Recently, leaf hyperspectral reflectance data has been used to train machine learning models using partial least squares regression (PLSR) to rapidly predict genetic variation in photosynthet...

Photosynthesis has become a major trait of interest for cereal yield improvement as breeders appear to have reached the theoretical genetic limit for harvest index, the mass of grain as a proportion of crop biomass. Yield improvements afforded by the adoption of green revolution dwarfing genes to wheat and rice are becoming exhausted and improvemen...

One way to increase yield potential in wheat is screening for natural variation in photosynthesis. This study uses measured and modelled physiological parameters to explore genotypic diversity in photosynthetic capacity (Pc, Rubisco carboxylation capacity per unit leaf area at 25°C) and efficiency (Peff,Pc per unit leaf N) in wheat in relation to f...

Greater availability of leaf dark respiration (Rdark) data could facilitate breeding efforts to raise crop yield and improve global carbon cycle modelling. However, the availability of Rdark data is limiting because it is cumbersome, time consuming or destructive to measure. We report a non‐destructive and high‐throughput method of estimating Rdark...

Improving photosynthesis to raise wheat yield potential has emerged as a major target for wheat physiologists. Photosynthesis-related traits, such as nitrogen per unit leaf area (Narea) and leaf dry mass per area (LMA), require laborious, destructive, laboratory-based methods, while physiological traits underpinning photosynthetic capacity, such as...

We examined the effects of leaf temperature on the estimation of maximal Rubisco capacity (Vcmax) from gas exchange measurements of wheat leaves using a C3 photosynthesis model. Cultivars of spring wheat (Triticum aestivum (L)) and triticale (x Triticosecale Wittmack) were grown in a greenhouse or in the field and measured at a range of temperature...

The world population is rising, placing increasing demands on food production. One way to contribute to food security is by improving yields of staple crops like wheat. Yield can be calculated from the product of plant biomass and harvest index (the ratio of grain yield to above ground biomass). Since harvest index of wheat has already reached its...

Leaf hyperspectral reflectance spectra may help to predict photosynthetic properties such as Rubisco (V cmax) and electron transport (J) capacity, chlorophyll or nitrogen content. We tested predictions using Partial Least Square Regression in five sets of wheat genotypes. The best prediction was for the chlorophyll content surrogate SPAD. As predic...

To exploit genetic variation in photosynthesis in wheat to increase yield potential, large germplasm collections need to be screened. Plant age, nutrition and environmental conditions need to be accounted for in order to differentiate between genotypic and environmental effects. Photosynthetic capacity is defined here as the amount of photosyntheti...

Carotenoids are antioxidant pigments that capture photons from the visible spectrum and protect plant tissues against photo-oxidation, which is related to photosynthesis rate and crop yield. Biosynthesis of carotenoids occurs in plastids, where they are synthesized via the mevalonate-independent pathway, whit more than 10 enzymes and an unknown num...

Carotenoids are antioxidant pigments that capture photons from the visible spectrum and protect plant tissues against photo-oxidation, which is related to photosynthesis rate and crop yield. Biosynthesis of carotenoids occurs in plastids, where they are synthesized via the mevalonateindependent pathway, whit more than 10 enzymes and an unknown numb...

Confirmation of the absence of xanthine dehydrogenase activity in has1 aba3-1, has2 aba3-1 and has3 aba3-1. Zymogram of total protein extracts from leaves of 21 day-old plants. Band corresponds to coloured product produced by xanthine dehydrogenase activity in the wild-type (WT). Similar results were obtained in 2 independent experiments. (TIF)

Symptom notation for Dickeya dadantii infection. The scale of infection is denoted by: 0: no symptom; 1: maceration limited to the inoculation point; 2: maceration extends from the infection point; 3: maceration covers half the lamina; 4: maceration spread over the whole lamina; 5: maceration spread over the whole leaf (lamina and petiole). (TIF)

Selection of has single mutants. (TIF)

Photosynthesis measurements. (TIF)

The has3 mutant is not a cyp707a1 mutant allele. A, False colour infrared image of the temperature of drought stressed plants showing that the F1 progeny of cyp707a1-1 crossed with has3 had colder leaves than the parental genotypes. B, F1 progeny of cyp707a1-1 crossed with has3 were less resistant to a progressive drought stress then the parental g...

Schematic representation of the procedure used for selection of has single mutants. Chromosomes bearing the HAS or ABA3 loci are represented as purple or blue bars, respectively, and the loci themselves as light blue or black lines, respectively. (TIF)

Photosynthesis is not modified in has mutants. Photosynthesis rates based on leaf net CO2 uptake (A) were measured as a function of Ci (internal CO2 molar ratio) under A, ambient oxygen (21%) or B, low oxygen (0.5%) conditions. PPFD during measurements was 800 µmol.m−2.s−1. WT, wild-type. Error bars represent SE values (n≥3). (TIF)

Primer sequences and number of recombinant F2 progeny for markers delimiting the has loci mapping intervals. (TIF)

Stomatal density is not modified in has mutants. Number of stomata measured on abaxial surface, black bars, or adaxial surface, white bars. WT, wild-type. Error bars represent SE values (n≥5). Similar results were obtained in 2 independent experiments. (TIF)

Induction of stomatal closure by 10 µM ABA in wild-type and has mutants. Stomata aperture ratios (width/length) were measured after a 2 h pre-treatment in the light in stomata opening solution followed by a 3 h incubation with or without 10 µM ABA. Error bars represent SE values (n = 40). No significant difference was observed in Student t-tests co...

Stomatal density measurement. (TIF)

The has2 mutation affects germination characteristics in accord with seed ABA hypersensitivity. A, Germination of mature, surface-sterilised seeds. The number of seeds with protruding radicles was scored and compared with the total number of seeds sown. B, paclobutrazol resistance of germinating seeds. The number of seeds with green cotyledons was...

On water deficit, abscisic acid (ABA) induces stomata closure to reduce water loss by transpiration. To identify Arabidopsis thaliana mutants which transpire less on drought, infrared thermal imaging of leaf temperature has been used to screen for suppressors of an ABA-deficient mutant (aba3-1) cold-leaf phenotype. Three novel mutants, called hot A...

This Theme aims to produce novel wheat germplasm with superior photosynthetic efficiency, superior photosynthetic capacity and hence higher anthesis biomass and yield potential (Parry et al. 2011). Improving photosynthesis is the cornerstone of the Wheat Yield Consortium (WYC) proposal in that it aims to provide the elevated carbón “push” which the...