<p class="western" style="margin-bottom: 0cm; line-height: 200%;" align="JUSTIFY"><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;">Vegetative propagation of arabica coffee plants selected by their agronomic value has been accomplished, routinely, for scientific purposes, through somatic embryogenesis and rooting of stem cuttings, in Brazil. Somatic embryogenesis is the election method when a very high number of cloned plants is demanded. Nevertheless, the costs of </span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"><em>in vitro</em></span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"> multiplication make difficult to explore it commercially. The experiments described herein aimed to amplify the number of </span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"><em>in </em></span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"><span lang="en-GB"><em>vitro</em></span></span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"> cloned plants</span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"><em>,</em></span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"> post acclimatization, to reduce costs. Different concentrations of an auxin translocation inhibitor and its association with a cytokinin were applied, as successive pulses, in the 3</span></span></span><span style="color: #000000;">^{<span style="font-family: Times New Roman, serif;"><span style="font-size: medium;">rd</span></span>}</span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;">, 8</span></span></span><span style="color: #000000;">^{<span style="font-family: Times New Roman, serif;"><span style="font-size: medium;">th</span></span>}</span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"> and 13</span></span></span><span style="color: #000000;">^{<span style="font-family: Times New Roman, serif;"><span style="font-size: medium;">th</span></span>}</span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"> months after transference to the greenhouse, on the same sets of Catucaí and Siriema </span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"><em>in vitro</em></span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"> cloned plants,</span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;">to induce sprouting.</span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"> At the 8</span></span></span><span style="color: #000000;">^{<span style="font-family: Times New Roman, serif;"><span style="font-size: medium;">th </span></span>}</span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;">month, the experiments with </span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"><em>in vitro</em></span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"> cloned Catucaí plants were reproduced in the nursery, for comparison. Best results were observed for the association 2,3,5-triiodobenzoic acid (TIBA) 1000 + benzylaminopurine 60 mg.mL</span></span></span><span style="color: #000000;">^{<span style="font-family: Times New Roman, serif;"><span style="font-size: medium;">-1</span></span>}</span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"> applied in the greenhouse, at the 13</span></span></span><span style="color: #000000;">^{<span style="font-family: Times New Roman, serif;"><span style="font-size: medium;">th</span></span>}</span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"> month, when 8.5 and 7.0 micro-cuttings above 1 cm in length were produced using sprouts taken from each Catucaí and Siriema acclimatized plant, respectively. Applying this treatment twice a year, and harvesting induced sprouts each six months after the induction treatments, approximately 15 plants per each acclimatized one can be produced. The most important effect of TIBA was the induction of sub-apical sprouting. Greenhouse would be the best environment to apply successive pulses of sprouting inducers to coffee </span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;"><em>in vitro </em></span></span></span><span style="color: #000000;"><span style="font-family: Times New Roman, serif;"><span style="font-size: medium;">cloned plants.</span></span></span></p><p class="western" style="margin-bottom: 0cm; line-height: 200%;" align="JUSTIFY"> </p>

This study aimed to establish a strategy for drought-tolerant selection in Arabica coffee genotypes in Brazil, combining field trials under natural conditions with controlled growth condition experiments. A group of genotypes was evaluated in the greenhouse using 28 morphological, anatomical, and physiological traits. In addition, the productivity of genotypes was evaluated in the field. Under water deficit in the greenhouse, 13 studied traits showed significant genetic variance. For these traits, the heritability coefficients estimated based on the progeny mean ranged from 65 to 92%. A selection index combined with predicted means was applied at these traits to select four progenies for drought tolerance under greenhouse conditions. Under field conditions, the selection applied to genetic values that favored positive genetic gains in four progenies, indicating the potential use of these cultivars for breeding advanced generations. The selection results of coffee plants under greenhouse conditions matched the selection results in the field in a water-deficit region by 50% based on productivity; thus, two genotypes (H419-3-3-7-16-11 and H516-2-1-1-7-2) were identified that have both the productivity and morpho-anatomical traits that confer greater drought tolerance. Finally, we discussed possible strategies for the development of drought-tolerant cultivars.

The development of more drought-tolerant cultivars is essential for the maintenance of global agricultural production. This study aimed to perform an early selection of drought-tolerant Coffea arabica genotypes by evaluating their functional divergence using morphological, anatomical and physiological analyses. Seedlings of 14 genotypes were subjected to the drought stress imposed by irrigation for 18 days. Growth and anatomical parameters, leaf water potential and gas exchanges were measured. Under irrigated conditions and prolonged drought (18 days), the divergence among the genotypes was determined mainly by morphological traits, such as leaf area, stem diameter and, consequently, shoot dry mass. Under moderate drought (14 days), parameters such as water potential, cuticle thickness, stomatal density, number of xylem vessels and water-use efficiency were important for the divergence of the group with the highest ability to maintain its water status. The genotypes 1, 2, 4, 11 and 12 have characteristics that contributed to the maintenance of water status, such as greater cuticle thickness, stomatal density, smaller number of xylem vessels and phloem thickness, bigger root length and greater water-use efficiency. The functional divergence combining morphological, anatomical and physiological analyses in response to the moderate drought indicated the early selection of the genotypes 1, 2,4, 11 and 12 as more drought tolerant during the seedling stage.