Classification Method of Rape Root Swelling Disease Based on Convolution Neural Network

Both the seedling stage and the adult plant stage of rape can be infected with root edema, and the damaged roots swell to form tumors of different sizes and shapes. The incidence of rape root swelling at the seedling stage reached 17%, and the average incidence at the adult plant stage was 15%, resulting in a 10.2% reduction in rape production. The average plant height, number of siliques, number of kernels per horn, 1000-seed weight and yield per plant of healthy plants were significantly higher than those of diseased plants. Grading root lesions can help trace the root causes of root lesions. However, the method of grading is often performed manually by professionals at present, which has the problems of low speed and low efficiency. In order to solve this problem, a method for grading rape root swelling based on deep convolutional neural network is proposed in this paper. Firstly, a rape root swelling model based on convolutional neural network and regional candidate network was established, and then implement it on the deep learning Tensorflow framework Model, and finally compare and analyze the results. The rape root swelling model uses the VGG16 network to extract the characteristics of the rape root swelling image. The regional candidate network generates the preliminary position candidate frame of the rape root swelling, and Fast-RCNN realizes the classification and positioning of the candidate frame. The results show that this method can achieve rapid and accurate detection of healthy, first-level tumors, second-level tumors, and third-level tumors of four-level rape root swelling, with an average accuracy rate of 84.12%. The experimental results show that the accuracy rate can reach more than 90%.

Responses of tomato (Solanum lycopersicum L.) plants to iron deficiency in the root zone

Iron deficiency induces a yellowing in the aerial part of plants, known as iron chlorosis, and reduces the growth, yield, and quality of the fruits. Understanding plant response to iron deficiency is essential for agronomic management. This study decoded the temporal response of tomato plants (Solanum lycopersicum L.) to iron deficiency by quantifying different vegetative parameters. Subapical root swelling in the first 2.0 mm and several shoot and root growth parameters were measured in plants grown in a nutrient solution with and without Fe, on different dates designated as days after transplantation (DAT). Correlations between the total chlorophyll concentration in young leaves and 22 morphological and physiological parameters were also calculated. The plants grown in the absence of Fe had a higher number of secondary roots at 3 DAT, compared to control plants. On the same date, subapical root swelling was also observed, particularly at 1.5 and 2.0 mm from the root tip. Those plants also had a lower chlorophyll content in young leaves and a higher ferric-chelate reductase activity (FCR; EC 1.16.1.17) in the roots. At 9 DAT, the overall vegetative performance (plant height, fresh weight of stems and leaves) was negatively affected. At the end of the experiment (14 DAT), significant correlations were found between chlorophyll and the studied parameters. In conclusion, tomato plants experienced a cascade of responses to Fe deficiency throughout nine days: firstly, root lateralization increased; later, root swelling was observed, and a decrease in leaf chlorophyll content was registered associated with an increase in root FCR. At the end, the biomass of tomato plants decreased.

Morfología de plántulas de Bursera Jacq. ex L. (Burseraceae) y sus implicaciones filogenéticas

Characters of seedlings from ten species of the genus Bursera were studied, in order to find additional taxonomic evidence. All species showed phanero-epigeal germination, developing a primary root system (axonomorphous root). Species included in section Bursera have a root swelling at basal level near the collar, and a slim hypocotyl. The cotyledonary leaves were multilobate in the ‘cuajiotes’ species group and three-lobed in species of B. simaruba complex. The species of Bursera sect. Bullockia showed a not swollen primary root system with a slim collar; a striate, lenticelled and swollen hypocotyl, and three-lobed cotyledonary leaves. There are four characters that can be considered important for phylogenetic analyses: (1) protophyll margin type, (2) protophyll venation, (3) form of cotyledonary leaves, and (4) the swolliness of the radicle. Groups like section Bullockia, the ‘cuajiotes’ and ‘mulatos’ are supported upon the distribution of characters.

Reproductive biology of two species of Kielmeyera (Guttiferae) in the cerrados of Central Brazil

ABSTRACTThe reproductive process of two species of Kielmeyera, K. coriacea and K. speciosa, sympatric in savanna areas in central Brazil, has been studied. The trees have similar pollination systems and dispersal mechanisms but distinct phenological behaviours. Fast germination after the beginning of the wet season, early root swelling forming a xylopodium which enables survival during the dry season, and recurrent sprouting from the swollen root system during the first years of development were features of an establishment syndrome common to both species. The seedling survival after establishment was high; after five years 64% of the seedling cohort of K. coriacea was still alive. These seedlings, in natural conditions, remain poorly developed and resprout recurrently from the soil during some years. The recruitment of adult plants seems to occur from this ‘seedling bank’. The reproductive process was higher in K. coriacea during most stages of the reproductive process which may explain the smaller population size and distribution range of K. speciosa. For both species, the reproductive process as a whole was mainly affected by biotic factors in the wet season and not by seasonal drought or periodic fire.