Growth differential related to wood structure and function of Eucalyptus spp. clones adapted to seasonal drought stress

Aim of the study: To evaluate the growth performance, wood density and anatomical features of four drought-tolerant Eucalyptus spp. clones, at 4 years, and to examine the relationships between these characteristics and some functional parameters. Area of study: The analyzed trees were from a clonal test installed in a region characterized by seasonal drought stress in central-western Brazil. Methods: Trees were felled, followed by obtaining dendrometric parameters and wood disk sampling to determine wood bulk density by x-ray densitometry, and morphometric parameters of fibers and vessels in order to evaluate the xylem hydraulic architecture. Lumen fraction (F), vessel composition (S) and hydraulic conductivity (Ks) were estimated. Results: Clone D (E. urophylla x E grandis) presented the highest growth rates, which was related to anatomical characteristics such as low relative frequency of wide vessels. High theoretical Ks does not necessarily imply higher growth rates and were related to lower wood densities. It is possible to infer that the better xylem adjustability of Eucalyptus trees in response to drought stress conditions is associated with increased vessel composition to the detriment of higher hydraulic conductivity. Research highlights: Vessel composition showed a greater variation among Eucalyptus genotypes and was positively associated with growth performance.

Morphological variation in the interspecific hybrid of Acacia (Acacia mangium × A. auriculiformis)

Acacia hybrid is an interspecific hybrid resulting from crossing between Acacia mangium and A. auriculiformis either naturally or artificially. This study aimed to determine the morphological variation of artificial Acacia hybrid, obtained by full-diallel control crossing. Observed sample trees were clones at the clonal test, established in 2011 in Wonogiri, Central Java. Tree samples were taken by selecting clones categorized into the superior, intermediate, and inferior clones based on their growth at one year of age, with three different clones in each category. Parameters to be observed were morphological characters including quantitative (tree height, diameter breast height, bole length, phyllode length and phyllode width) and qualitative (stem form, stem straightness, bark type, bark color, phyllode shape, phyllode apex shape, conspicuousness of the main vein, and petiole color). The data quantitative and qualitative were then scored and analyzed using NCSS series 12 software for cluster analysis. The results showed that morphological characters of Acacia hybrid clones varied across the tree categories. Furthermore, the dendrogram showed that the characters of Acacia hybrid grouped into two clusters: Cluster A dominated by superior and most intermediate clones, and Cluster B dominated by inferior clones. The study result implies the use of morphological characters of Acacia hybrid to select the hybrid vigor in a breeding program.

Genetic parameters in a clonal test of Tectona grandis in Mato Grosso, Brazil

Teak (Tectona grandis) is a high-value timber species in tropical regions. In Brazil, although teak has a high productivity, there are few studies related to its genetic improvement. This work aimed to estimate genetic parameters and evaluate potential gains of selection in a clonal test of teak installed in the state of Mato Grosso, Brazil. The experimente is in a randomized block design, with five replications, 3x3 m spacing, 22 treatments, and plots with six individuals. At five years, the genotypes were evaluated for survival (S), tree total height (H) and girth at breast height (GBH). There was significance and feasibility of selection for S and GBH. For H, the result was not significant, indicating few gains with the selection. The genetic parameters of clonal mean heritabilities and accuracy were of moderate magnitude for S and GBH and low for H. To best of our knowledge, this is the first work that estimates genetic parameters in a clonal teak test in the field in Brazil.

Morphological descriptors for the characterization of teak clones (Tectona grandis L.f.) in plantations

Aim of study: The objective of this work was to identify possible morphological descriptors for teak clones, in order to support the cultivars protection process of this species.Area of study: This experiment was carried out in ‘São José dos Quatro Marcos’, Mato Grosso, midwest Brazil.Material and methods: A teak clonal test, assessing 18 clones, was evaluated at the ages of 29 and 41 months by means of 41 morphological characteristics, related mainly to the branches, leaves and trunk. The clonal test was established in a randomized block design composed by three blocks, each block containing 18 plots, one for each clone. Each plot had 36 plants, but only the innermost five individuals were selected and evaluated. The information was organized in a presence and absence matrix. Subsequently, genetic similarity measures were estimated, by means of the Jaccard index, and a clustering was performed by the Unweighted Pair Group Method using the Arithmetic averages (UPGMA) method.Main results: A total of 26 and 28 morphological characteristic that exhibited DHS (distinction, homogeneity and stability) were identified at the ages of 29 and 41 months, respectively. Of these, 17 characteristics showed the same behavior at 29 and 41 months of age. However, it is important to emphasize that the evaluation must be performed under the same planting conditions in which these descriptors were developed.Research highlights: These 17 morphological characteristics can compose the list of potential morphological descriptors to be used in the process of teak clones/cultivars protection.Keywords: cultivars protection; morphological characteristics; distinction, homogeneity; stability.

Visual selection of Urochloa ruziziensis genotypes for green biomass yield

The breeding program of Urochloa ruziziensis evaluates many genotypes in initial phases. Evaluations through grades might make the selection less costly. The aim of this study was to verify the efficiency of visual selection for green biomass yield in relation to different selection strategies, such as mass selection by phenotypic mean, BLUP (Best Linear Unbiased Prediction) and at random. For this purpose, 2,309 regular genotypes were evaluated in an augmented block design in two cuts. The evaluators gave grades for plant vigor, and later, the plots were measured for green biomass yield. The coincidences of the selected genotypes were estimated by different selection strategies. Then, 254 clones of the genotypes selected in different strategies were evaluated in a clonal test in a triple lattice design in four cuts. The statistical analyses were performed in SAS using the Mixed procedure. The regular genotype level and clone-mean basis heritabilities were 31.16 and 62.91%, respectively, for green mass yield. The expected selection gains were 21.09% (visual), 25.43% (phenotypic mean), and 27.5% (BLUP). Moreover, the realized heritabilities for these strategies were 15.58, 11.87, and 15.86%, respectively, which might be associated with genotype by environment interaction. Therefore, the visual selection could be a useful strategy in initial phases of a U. ruziziensis breeding program because the efficiency was moderate to high in relation to phenotypic mean and BLUP.

Pengembangan klon Sukun (Artocarpus altilis (Park.) Fosberg.) unggulan untuk mendukung ketahanan pangan

Breadfruit (Artocarpus altilis) is one of multipurpose tree species that their wood, bark, fruit and leaves can be utilized for human life. The main product of breadfruit is its fruit as one of the potential food sources that has a fairly high nutrient content and is widely consumed as an additional food and even traditional staple foods such as in some countries the Pacific region. The challenge in developing breadfruit as an alternative food source for the community is to prepare the plant material of superior breadfruit clones which have high fruit production and have enough nutrients and chemicals as a source of food and medicinal ingredients. Based on the clones selection at the clonal test plantation in Gunungkidul, Yogyakarta obtained 5 excellent breadfruit populations representing breadfruit cultivars in Indonesia, namely Cilacap, Yogyakarta, Bali island, Bone and Manokwari. To ensure the availability of seedlings of superior breadfruit clones, the development of planting stocks production techniques is carried out by root cuttings, shoot cuttings and stem cuttings in the nursery that showed better growth succeess (70-100%). Furthermore, information dissemination is carried out to increase efforts to develop breadfruit by the community / user. Breadfruit planting activities are carried out to increase the availability of food reserve forests in the future, both independently and collaboratively with stakeholders who interested in developing of breadfruit plantations.

Genetic progress with selection of Coffea canephora clones of superior processed coffee yield

ABSTRACT: The aim of this study was to select Coffea canephora clones of superior processed coffee productivity based on the estimates of the genetic parameters and of genetic progress with the plant selection. For this, the production of processed coffee from 130 clones was evaluated from 2014 to 2016 in a clonal test, installed in randomized complete blocks with four plants per plot and six replications, spaced 3 × 2m at the experiment station Embrapa Rondônia in the municipality of Ouro Preto do Oeste - RO. The estimation of genetic parameters and prediction of genotypic values were performed using REML/BLUP procedure (Restricted Maximum Likelihood/Best Unbiased Linear Prediction). Estimates of the genetic parameters confirmed the predominance of the genetic component in the expression of this trait, indicating the possibility of obtaining gains with the plant selection. Genetic progress of processed coffee productivity from the selection of 10% of the best clones was 49.88%, which is equivalent to an increase in average productivity from 42.57 bags.ha-1 to 66.95 bags.ha-1. The use of the harmonic mean of the genetic values helped to identify the clones of superior performance, with higher adaptability and stability for the northern region of Brazil.

Pertumbuhan Tunas Beberapa Klon Jati Terseleksi setelah Pemangkasan di Persemaian

Kebun pangkas jati dibangun dalam rangka memperbanyak klon-klon terseleksi di plot uji klon jati. Biasanya, kebun pangkas dibangun pada lahan dengan luasan tertentu. Penelitian ini dilakukan untuk mengetahui kemampuan pertunasan beberapa klon jati pada kebun pangkas jati di tingkat persemaian. Penelitian ini disusun dengan menggunakan rancangan acak kelompok dengan perlakuan 10 klon jati yang diulang sebanyak 3 kali dengan 10 tanaman pangkasan dalam setiap ulangan. Klon yang digunakan adalah hasil seleksi uji klon jati di Gunung Kidul, Yogyakarta.Hasil pengamatan menunjukkan perlakuan klon berpengaruh nyata terhadap karakter jumlah tunas, panjang tunas, diameter tunas, jumlah ruas dan jumlah daun. Hasil pengamatan menunjukkan untuk pertumbuhan tunas pada umur 6 minggu diperoleh rerata jumlah tunas 4,33; panjang tunas 9,09 cm; diameter tunas 5,91 mm; jumlah ruas tunas 2,38, dan jumlah daun 5,09 helai. Persentase hidup tanaman setelah pemangkasan bervariasi antar klon antara 86,67-96,67%. Hasil penaksiran nilai heritabilitas untuk pertumbuhan tunas termasuk kategori sedang sampai tinggi yaitu sebesar 0,41-0,73.The Shoot Growth of Several Selected Clones of Teak after Coppicing in the NurseryAbstractTeak hedge garden was established to multiply several selected clones of teak from clonal test trial. It was usually established on a certain arable land. This study was conducted to determine the ability of various teak clones in the sprouting hedge garden which was established in the nursery. The study was arranged in randomized complete block design with 10 clones, 3 replications, and 10 individual ramet per replication. The tested clones were selected from a teak clonal test in Gunungkidul, Yogyakarta. The results showed that clones significantly affected the shoot growth: number, length, diameter, number of internode and number of leaf. At 6 weeks after hedging, the average of shoot number was 4.3, shoot length of 9.1 cm, shoot diameter of 5.9 mm, the number of internode of 2.4, and the average number of leaves was 5.1. The survival rate of plants after hedging treatment was varied from 86.7 to 96.7 %. Estimated heritability for shoot growth was categorized as moderate to high, varying from 0.41 to 0.73.

Genotypic value in hybrid progenies of Panicum maximum Jacq.

ABSTRACT: Genetic breeding of forage plants has increasingly contributed to the release of more productive plants. In this regard, evaluating the genotypic value is essential when aiming to rank genotypes based on the mean free of environmental factors. Therefore, this study aimed to predict the genotypic value of agronomic and nutritive value characters of three progenies of Panicum maximum. Hybrids were evaluated in a clonal test in an incomplete-randomized design with three treatments (progenies 1, 2, and 3) and two replications (clones). Six harvests were performed at 25cm from the ground level throughout one year. Progeny 2 provided better results for total and leaf dry mass yield, regrowth, and height, and lower incidence of leaf spot. Progenies 1 and 3 had a better response for qualitative characters such as higher crude protein and digestibility and lower lignin and fiber content. Hybrid progenies of P. maximum have forage characters of interest for breeding, and when using ‘Mombaça’ grass as parents, the progeny stands out for leaf production and resistance to leaf spot and for ‘Tanzania’ grass as parent has resulted in better forage quality.

Genetic Parameter Estimation of Teak Clonal Test At 5 Years Old in Wonogiri, Central Java

Trial research of teak clones was located in Wonogiri, Central Java. This research was conducted in order to evaluate the growth performance of teak clones that can be developed for forest plantation and private forest. Establishment of teak clones test was conducted in 2002 using 20 clones with Randomized Completely Block Design/RCBD consisting of 5 ramets and 5 replications with plant spacing of 2 m x 6 m . The second plot was established in 2005 using 100 clones with RCBD that consisted of 3 ramets and 5 replications with spacing of 2 m x 6 m. The observation and measurement on height and diameter at breast height/dbh were carried out periodically in every year to determine the level of plant growth The results showed that the average growth at the age of 5 years in two test plot clones are height from 8,73 to 9,97 m , tree diameter from 8.61 to 13.14 cm and tree volume estimated 0,046 - 0,103 m3. Estimated heritability clones of tree height and diameter were 0,18; 0,29 in plot 1 and 0,32; 0,38 in plot 2.