Search

Evaluating the wood properties of poplar clones to be used in fast-growing and high-yield plantation and select superior clones are critical to increase both quantity and quality of wood production. This study determined the fiber morphology, chemical composition and pulping of nine introduced poplar clones after six growing seasons and assessed their suitability for pulping and papermaking. Results showed that the fiber morphological differences among nine clones were not obvious. Fiber with length less than 1.0 mm accounted for 91.7% of the total fibers which were mainly short. Taro had longer and thinner fibers with the largest length-width ratio, followed by Bellatto, whereas Lambro owned the shortest and thickest fiber with a small length-width ratio. Neva had the Runkel ratio much high as 1.0, which was larger than that of other eight clones. From the point of view of chemical composition, Taro contained low content of ash, cold/hot water-soluble content, benzene ethanol-soluble content, and lignin, but higher content of holocellulose. 1% sodium hydroxide-soluble and pentosan contents were 20.47% and 22.62% respectively, on average; thus Taro can be suggested as good-quality industrial material applied in pulping and papermaking. On the contrary, Bellotto got imperfect overall performance, which was considered comprehensively before selection.

Leaf morphology in Populus L. varies extensively among sections, species and clones under strong genetic control. P. nigra L. (section Aigeiros), with large and triangular leaves, is a commercial forest tree of economic importance for fast growth and high yield in Europe. P. simonii Carr. (section Tacamahaca) with small land rhomboid ovate leaves performs cold and dry resistance/tolerance in the semi-arid region of Northern China. Leaf morphological traits could be used as early indicators to improve the efficiency of selection. In order to investigate the genetic variation pattern of leaf morphology traits, estimate breeding values (combining ability), as well as evaluate crossing combinations of parents, 1872 intersectional progenies from eight families (P. simonii &times, P. nigra) and their parents were planted with cuttings for the clonal replicate field trial in Northern China. Four leaf size traits (area, perimeter, length, width) and roundness were measured with leaf samples from the 1-year-old clonal plantation. Significant differences regarding leaf traits were found between and among three female clones of P. simonii from Inner Mongolia, China and six male clones of P. nigra from Casale Monferrato, Italy. The genetic variation coefficient, heritability and genetic variance component of most traits in male parents were greater than these of female parents. Heritability estimates of male and female parents were above 0.56 and 0.17, respectively. Plentiful leaf variations with normal and continuous distributions exited in the hybrid progenies among and within families with the genetic variation coefficient and heritability above 28.49 and 0.24, respectively. Heritability estimates showed that leaf area was the most heritable trait, followed by leaf width. The breeding value ranking of parents allowed us to select the parental clones for new crosses and extend the mating design. Two male parental clones (N430 and N429) had greater breeding values (general combining ability, GCA) of leaf size traits than other clones. The special combining ability (SCA) of the crossing combination between P. simonii cl. ZL-3 and P. nigra cl. N430 was greater than that of others. Eight putatively superior genotypes, most combined with the female parental clone ZL-3, can be selected for future testing under near-commercial conditions. Significant genetic and phenotypic correlations were found between five leaf morphology traits with the coefficients above 0.9, except for leaf roundness. The results showed that leaf morphology traits were under strong genetic control and the parental clones with high GCA and SCA effects could be utilized in heterosis breeding, which will provide a starting point for devising a new selection strategy of parents and progenies.

Lettuce (Lactuca sativa L.) is a leading greenhouse-grown vegetable. However, nitrate (NO3&minus, ) accumulation in leaves remains a major issue. The aims of this research were: (i) to test the modified intermittent Nutrient Film Technique (NFT) in the cultivation of soilless lettuce in which plants are grown on peat blocks in trays and supplied with an intermittent flow of nutrient solution, and (ii) to calibrate the fertilization scheme to increase yield performance, while keeping NO3&minus, concentration under control. Two greenhouse trials were performed between autumn 2013 and spring 2014. Results showed that a 30-day cycle is the optimum duration in terms of fresh biomass yield, both for autumn and spring cultivation. Reducing N fertilization in the last cropping days never affected NO3&minus, concentration in leaves during autumn trial, due to unfavourable growing conditions. Conversely, suspension of fertilization 2 days before harvest had a consistent effect during the spring trial, when NO3&minus, concentration in leaves was highly reduced (from 20 to 36%) without yield penalties. Thus, suspending fertilization 2&ndash, 4 days before harvesting in intermittent NFT may reduce, on average, NO3&minus, accumulation by 29&ndash, 58% and the fertilization rate by 7&ndash, 16%, respectively. Yet, growing conditions are crucial to make this system effective.

La coltivazione del pioppo in sistemi silvoarabili ed i nuovi cloni ibridi a maggiore sostenibilità ambientale (cloni MSA) rappresentano due importanti fattori innovativi che potrebbero contribuire al rilancio della pioppicoltura italiana. Nei sistemi silvoarabili, i filari arborei intervallati alle colture agricole aumentano la sostanza organica ed il Carbonio nel suolo, mitigando i cambiamenti climatici. Le radici degli alberi riducono la lisciviazione dei nitrati, con una forte azione di fito-depurazione di acqua e suolo da molti contaminanti. Per i suddetti benefici, i Piani di Sviluppo Rurale di alcune Regioni prevedono finanziamenti per i sistemi silvoarabili con pioppo (Mis. 8.2, che copre 80% costo impianto pioppo e manutenzione 250 EUR/ha per 5 anni). I nuovi cloni ibridi MSA presentano una maggiore resistenza alle principali patologie della coltura, determinato minori costi di produzione (-17%) e minore impatto ambientale (-70%). L'assenza di trattamenti fitosanitari alla chioma delle piante arboree semplifica notevolmente la gestione delle eventuali colture erbacee consociate. Nuovi impianti silvoarabili sono stati realizzati, sia con il clone I-214 (2013, 9 ha, Azienda Casaria, PD), che con i nuovi cloni MSA (2018, Sasse Rami -RO, 7,5 ha; 2019, Vallevecchia, 20 ha; 2019, Sant'Anna, Uni. Pisa, 22 ha). L'obbiettivo del contributo è presentare i risultati della convenienza finanziaria dei sistemi silvoarabili del pioppo rispetto alle coltivazioni in purezza, per un ciclo colturale di 10 anni. I dati per le simulazioni economiche sono stati in parte ottenuti dall'impianto di Casaria (prima metà del ciclo), in parte dalla bibliografia per stabilire l'andamento della produttività delle colture consociate nella seconda metà del ciclo. Per il pioppo silvorabile è stato considerata una densità di 30 piante ad ha, con distanze tra i filari di 30 m. Sono considerati 5 scenari di coltivazione per una valutazione economica. È stato calcolato il VAN (valore attuale netto, EUR ha-1), con attualizzazione dei costi e dei ricavi, per scenario per la durata di 10 anni con tasso di sconto del 3% (i=0,03). Non è considerato il beneficio fondiario. Sono stati considerati i seguenti 5 scenari: A, grano e soia in avvicendamento con filari di pioppo, cloni MSA; B: grano e soia in avvicendamento e barbabietola anni alterni con filari di pioppo, cloni MSA; C, grano e soia in avvicendamento; D, barbabietola; E: pioppeto in piantagione con cloni MSA, densità 278 piante ettaro, con produzione finale di 150-180 t/ha, prezzo piante in piedi 80 EUR/t, contributo 60% costo impianto PSR 8.1 . Per le colture agrarie è stato considerato il contributo del Premio Unico Aziendale. I valori di VAN min (minimo) e VAN max (massimo) per i casi A e B si differenziano esclusivamente per il prezzo del pioppo applicato come prezzo da ripa (40 EUR/t) per il minimo, e prezzo da piantagione (80 EUR/t) nel caso di massimo ricavo. Dai dati di accrescimento delle piante di pioppo ottenuti nei primi anni di crescita si stima che a dieci anni ciascuna pianta possa produrre 7-8 quintali di legno destinabili per gran parte all'industria dei pannelli. Dal punto di vista economico i risultati di A e B (pioppo silvoarabile) si dimostrano superiori a quelli delle colture erbacee (seminativi) in purezza quando le piante arboree in consociazione raggiungono buone produzioni quanti-qualitative nel turno. Le ricerche proseguono per determinare l'andamento delle produzioni agricole consociate nella seconda metà del turno del pioppo (6-10 anni) e l'influenza della bassa densità d'impianto (30 piante ad ha) sulla forma del fusto (qualità del legno) dei nuovi cloni MSA. Contributo presentato con ricerche condotte nel progetto e H2020 AFINET e PSR Veneto Carter.

Tomato hybrids obtained from homozygous progeny of line 30-4, engineered for Tomato spotted wilt virus (TSWV) resistance, were tested under field conditions in two locations with their corresponding nontransgenic hybrids. No transgenic hybrid became infected, but 33 to 50% of plants of each nontransgenic hybrid became infected with a severe reduction of marketable fruit production. The transgenic hybrids conformed to the standard agronomic characteristics of the corresponding nontransgenic ones. Fruit were collected from the nontransgenic plots included in the experimental field and from border rows, and seed were used to estimate the flow of the transgene via pollen. No transgene flow was detected in the protected crops; however, in the open field experiment, 0.32% of tomato seedlings were found to contain the genetic modification. Immunity to TSWV infection in 30-4 hybrids was confirmed in laboratory conditions using mechanical inoculation and grafting. Thrips inoculation in leaf discs of line 30-4 demonstrated that TSWV replication was inhibited at the primary infection site but not in leaf discs of a commercial hybrid containing the naturally occurring resistance gene Sw-5. Due to the high economic value of tomato crops worldwide and the importance of TSWV, the engineered resistance described here is of practical value for breeding into cultivars of commercial interest, because it could be combined with naturally occurring resistance, thus greatly reducing the ability of the virus to develop resistance-breaking strains.

In vitro shoot regeneration ability of 17 (7 Italian and 10 Hungarian) bell pepper genotypes was investigated using excised cotyledons and rooted hypocotyls as explants. Most of the Italian genotypes and two of the Hungarian genotypes responded well, producing shoots from rooted hypocotyls. Only two genotypes (one Italian and one Hungarian) gave a weak response using cotyledons. For direct shoot induction in these explants, in addition to the methods cited in the relevant papers, a new method was applied using thidiazuron as a cytokinin. Shoots were successfully regenerated from cotyledons of two Italian and two Hungarian genotypes using thidiazuron which were considered to be non responsive to the usual methods.

The heterogeneity of pedoclimatic conditions and the farmer selection for adaptation to local tastes and uses have favored the maintenance in cultivation in Italy of numerous pepper (Capsicum annuum L.) landraces. We have used amplified fragment length polymorphism (AFLP) fingerprinting and morphological variation in fruit type to assess the diversity of 19 pepper ecotypes representative of the autochthonous germplasm. Principal component analysis grouped together triangular and blocky fruited types, while elongate types were subdivided into long and half long, differing mainly with respect to the length/diameter ratio. The half-long types were divided into two further clusters on the basis of overall dimension, weight, and flesh thickness. Genetic similarities between the ecotypes were calculated from AFLP data and this allowed the separation of the accessions into two major and three minor clusters. One major cluster comprised five ecotypes with blocky or triangular fruits, while the other contained nine ecotypes with long or half-long fruits. AFLP markers were successful in both detecting genetic diversity and determining genetic relationships in Italian pepper germplasm. They also made it possible to distinguish most of the provenances within a given landrace, and to identify pairs of genetically similar ecotypes carrying different names. We believe that our analyses will help in the identification of rational strategies for the preservation of Italian pepper genetic resources.