Transcriptional regulation of MdPIN7 by MdARF19 during gravityinduced formation of adventitious root GSA in self-rooted apple stock

Self-rooted apple stock is widely used for apple production.However,the shallowness of the adventitious roots in self-rooted apple stock leads to poor performance in the barren orchards of China.This is because of the considerable difference in the development of a gravitropic set-point angle(GSA)between self-rooted apple stock and seedling rootstock.Therefore,it is crucial to study the molecular mechanism of adventitious root GSA in self-rooted apple stock for breeding self-rooted and deep-rooted apple rootstock cultivars.An apple auxin response factor MdARF19 functioned to establish the adventitious root GSA of self-rooted apple stock in response to gravity and auxin signals.MdARF19 bound directly to the MdPIN7 promoter,activating its transcriptional expression and thus regulating the formation of the adventitious root GSA in 12-2 self-rooted apple stock.However,MdARF19 influenced the expression of auxin efflux carriers(MdPIN3 and MdPIN10)and the establishment of adventitious root GSA of self-rooted apple stock in response to gravity signals by direct activation of MdFLP.Our findings provide new information on the transcriptional regulation of MdPIN7 by auxin response factor MdARF19 in the regulation of the adventitious root GSA of self-rooted apple stock in response to gravity and auxin signals.

Vegetative Habitus and Fruit Production of Self-rooted Cherry Cultivar ＇Hedelfingen＇ Wild Type and Somaclonal Grafted on ＇Gisela 6＇ and ＇Colt＇ Rootstock

The study considers the morphological and physiological behaviour of self-rooted sweet cherry CV （Cultivar） ＇Hedelfinger＇ wild type （H） and somaclonal （HS） grafted on ＇Gisela 6＇ and ＇Colt＇ rootstock. The somaclonal showed reduced vegetative vigour without any variation of the natural tree＇s architecture. The rootstock ＇Gisela 6＇ caused change in genotype habitus inducing a spreading shape, while ＇Colt＇ increased trunk diameter and height. Fruit quality and size were not affected by genotype nor rootstock. ＇Gisela 6＇, from these preliminary data, had proved the most suitable rootstock for both genotypes since it reduced the tree size and vigor and induced early bearing and the production of a greater number of fruiting spurs.

Study on the Substrate Culture Techniques of Self-root Watermelon

In order to further improve the yield and quality of self-root watermelon and realize the continuous planting of self-root watermelon in the same field,this paper described the cultivation of self-root watermelon using a compound substrate as the cultivation medium.

Resistance of Grafted Tomato with Guozhen 1 as Stock against Root Knot Nematodes in Field

[Objective] This study aimed to study the resistance of grafted tomato with Guozhen 1 as stock against root knot nematodes. [Method] Tomato seedlings were grafted with Guozhenl （T1） and Solanum torvum （T2） as the rootstock, respectively. Self-rooted tomato seedlings were treated as the control （CK）. The resistance of tomato against root knot nematodes was compared among the three treatments. [Result] Compared with those in the T2 and CK groups, the yield of tomato in the T1 group was increased by 17 436.75 and 31 753.65 kg/hm2 respectively, the plant height was increased by 10.55 and 14.54 cm respectively （P〈0.05）, and the stem diameter was increased by 0.56 and 1.13 cm respectively （P〈0.05）. The disease indexes of root knot nematodiasis in the three treatments were 0.55, 10.42 and 45.31, respectively, and there were significant differences among them （P〈0.05）. [Conclusion] This study will provide a theoretical basis for the control of root knot nematodes in tomato by grafting.