Using compact varieties SC205, GR4 and umbrella varieties SC12, SC15 as the experimental materials, five treatments of 9, 36, 63, 90 leaves remained and no leaves removed were designed to study the differences of chlorophyll fluorescence and fresh tuber root yield to clarify the differences of chlorophyll fluorescence of functional leaves in different growth stages and leaves remained treatments and the effects of leaves number on fresh tuber root yield. The results showed that with the increase of leaves, the fresh tuber root yield increased, and the tuber root number, the fresh weight of stems and leaves and the harvest index increased first and then decreased. The average of tuber root yield per plant of 9, 36, 63, 90 and no leaf removed treatments was 0.94 kg, 2.22 kg, 2.65 kg, 2.91 kg and 3.35 kg, respectively. The maximum fluorescence yield (F_m) and maximum quantum yield (F_v/F_m) of compact varieties were higher than those of umbrella varieties. F_m and F_v/F_m of compact varieties was 0.885 and 0.739, respectively, and those of umbrella varieties was 0.838 and 0.707, respectively. The minimum fluorescence yield (F₀) of compact type was smaller than that of umbrella type, and that for the two plant type varieties was 0.219 and 0.231, respectively. F₀, F_m, F_v/F_m, ETR and Y(Ⅱ) decreased with the progress of leaf removed. With the increase of PAR, ETR increased gradually, and Y(Ⅱ) decreased sharply first and then slowly. The variation trend of chlorophyll fluorescence of cassava varieties with different plant types was the same, but the variation rule of different leaves was different. The ETR and Y(Ⅱ) of cassava functional leaves increased slightly when the number of leaves remained was small.

Edible cassava is an important food crop in the world and a characteristic potato crop in South China. New edible varieties with high β-carotene and excellent comprehensive quality are one of the important directions of cassava breeding. Manihot esculenta Crantz cv. Gui 9 was obtained from immature fruits, using embryo rescue technology, which were harvested from in-bred crossing population using XX048 as the female. The main characters of the variety were erect plant type, tubers distributed horizontally, cylindrical conical in shape, tubers of light brown skin, pink endothelium and orange flesh. The fresh tuber yield was (45.12±7.04) t/hm² and (40.84±3.88)t/hm² respectively in the regional test and production test. The starch content of fresh tuber detected was 26.3%, β-carotene content was 454 μg/100 g, hydrocyanic acid content was 10-20 mg/kg, tatal sugar content was 2.0 g/100 g, dietary fiber and potassium content was 4.43 g/100 g and 553 mg/100 g respectively. Gui 9 is an edible cassava variety in China with the highest β-carotene content in tuber at present, rich in β-carotene, dietary fiber and minerals, fresh taste crisp and sweet, known as "carrot cassava", with unique advantages in color and taste in cooking and making cassava juice. Gui 9 has high yield and strong adaptability with moderately resistance to cinnabar Tetranychus mites, and is suitable for dense planting and mechanical harvesting. It could be popularized in cassava producing areas such as Guangxi, Guangdong, Hainan and Jiangxi provinces. The breeding of Gui 9 would provide variety support for the development of cassava food, and promote the quality improvement, efficiency increase and sustainable development of cassava industry.

Cassava is the sixth-important grain crop in the world and the major cash crop in Southern China. Now cassava related industries play an important role in the local agricultural economy. Various kinds of diseases often happen and cause serious economic losses in the field, which become an important issue. This paper briefly reviewed the progress of cassava disease research, including the slow development stage from the founding of the P. R China to the 1980s, the fast development stage from the 1990s to the 2010s, and the rapid development stage after the 2010s. The latest research progress is the core part of this paper. Currently, there are four categories and eleven kinds of diseases that harm cassava in China. Cassava bacterial blight (CBB) is the most serious disease, and brown leaf spot occures in the largest area. Cassava mosaic disease (CMD) is the worst disease in the world, which has invaded mainland China. Chinese Academy of Tropical Agricultural Sciences and other institutions have launched the research of disease database construction and intelligent monitoring technology. The researcher had estimated the risk of five kinds of dangerous disease to cassava planting industry of China. For CMD and cassava brown streak disease, the research on the resistance evaluation of the main varieties, damage mechanism of virus, and detection methods were studied. As far as CBB, monitoring technology, genome sequencing of pathogen, pathogenic and copper resistant mechanisms, genetic variation of pathogen populations, selection of resistant germplasm and its function mechanism were investigated. The effective bactericide for CBB was screened, the efficient spraying and biological control technology were formed, along with the stem disinfection method was popularized in the field. In term of CMD, the occurrence area, virus identification, key factors for long range diffusion were confirmed in China, and significant advance was achieved in virus damage and propagation mechanism. The advance of monitoring and control technology on another seven kinds of common diseases was also expounded in this paper. With the development of the national economy, there have been new trends in China's cassava planting industry, such as food consumption and scaling planting. The authors further look forward to the number of participating institutions, the speed of scientific research progress, the boosting role of multidisciplinary integration, and new research hotspots will emerge in the future. This article would help relevant practitioners to better understand the current situation and research progress of cassava diseases in China, and also provide a reference for the research and application of monitoring technologies of other crop diseases in tropical areas.

The study of source/sink relationship has important theoretical research and technical application value in crop yield and quality formation. With the interdisciplinary integration of crop genetics and breeding, plant physiology and molecular biology, the study of source-sink relationship has made important progress in recent years by integrating molecular biology techniques, plant hormone signal transduction and many other new technologies and methods. In this paper, the research progress is reviewed from two aspects: source/sink relationship theory and regulation. The mechanism of glucose metabolism and hormone regulating source/sink relationship was emphasized, and the mechanism of cultivation measures improving yield by coordinating source/sink relationship was analyzed. Combined with the research progress on the mechanism and regulation of rubber trees, an important tropical cash crop. This lay a foundation for the theory of source/sink relationship in natural rubber industry and provide technical guidance for the creation of rubber latex flow control technology.

Ploidy identification is one of the basic tasks for germplasm resources and new variety breeding of tropical flowers. In this study, flow cytometry was used to identify the ploidy level of Cymbidium hybrid seedlings. aiming at the key links such as the type of dissociated liquid, the tissue organ of the test material, evaluation indexes such as the nuclear dissociation, the clear degree of the main peak, the easy degree of sampling, and the coefficient of variation. A technique system was established and the stomatal traits of different ploidy were analyzed. The results showed that CyStain UV Precise P was the best of the three dissociated liquid and young leaves were most suitable. Six triploid and two tetraploid were identified from the offspring of the three hybrid combinations. There were significant differences in stomatal length, width and density between different ploidy (P<0.05). The rank of stomatal length and stomatal width was tetraploid>triploid>diploid, while stomatal density was reversed. This study is valuable for the polyploid selection and use of different ploidy germplasm resources for cross breeding of Cymbidium hybrid.

Phalaenopsis arunachalensis K. Gogoi & Rinya is reported as a little known species from Medog, Tibet Autonomous Region, China. The detailed morphological descriptions and photos are also provided. This species is similar to P. honghenensis F. Y. Liu, P. wilsonii Rolfe and P. taenialis (Lindl.) Christenson & Pradhan. However, this species has a minutely spurred that bends down, the free part of lateral lobes which are less than half length of the mid-lobe, and dagger-like of lateral lobes ends, which can distinguish from other species.

The present study revealed the effects of chemical fertilizer reduction patterns on growth, cane yield and fertilizer utilization rate of sugarcane, in order to provide a theoretical basis for the application of mulched drip fertigation and find out the best pattern to reduce fertilizer in sugarcane. Seven different treatments were conducted: no fertilization (CK₀), conventional fertilization (CK₁), mulched drip irrigation + conventional fertilization (CK₂), mulched drip fertigation T₁₀₀ (fertilizer amount equated with CK₁) and T₈₀, T₇₀, T₆₀ (20%, 30% and 40% reduction of fertilizer amount of T₁₀₀). Main agronomic characters, cane yield, sucrose content, sugar yield, economic benefit and nutrient utilization rate of sugarcane were measured in the seven different treatments. The results showed that compared with CK₁, the millable stalk number in CK₂ increased significantly, the tillering rate, plant height, millable stalk number and stalk formation rate in T₁₀₀ were all improved significantly, the effective stalk number and stalk formation rate in T₈₀ and T₇₀ were improved significantly. Compared with CK₁, the cane yield in CK₂, T₁₀₀, T₈₀ and T₇₀ increased significantly by 13.64%, 32.20%, 27.00% and 20.18%, respectively. In the different drip fertigation treatments, there was no significant differences for cane yield between T₁₀₀ and T₈₀, but the cane yield for T₇₀ and T₆₀ decreased significantly in contrast to T₁₀₀. There was no significant difference in sugar content among the different drip fertigation treatments. The change trend of sugar yield and cane yield among the treatments was consistent. Sugar yield in T₁₀₀ and T₈₀ was higher than that in other treatments, and there was no significant difference between that in T₁₀₀ and T₈₀. Compared with CK₁, the net benefit in T₁₀₀ and T₈₀ increased significantly by 4534.4 yuan/hm² and 3953.8 yuan/hm², respectively. The net benefit in T₇₀ and T₆₀ decreased significantly compared with T₁₀₀, and the net benefit in T₆₀ was even 2350 yuan/hm² lower than that in CK₁. The fertilizer utilization rate of all drip fertigation treatments was significantly higher than that of CK₁, and the average utilization rates of nitrogen, phosphorus and potassium fertilizers in T₈₀ were the highest in all the treatments, reached 48.36%, 27.70% and 68.95%, respectively, which was 28.42, 17.95 and 30.71 percentage points higher than that of CK₁, respectively. Overall, in the middle fertility of laterite soil, the application of mulched drip fertigation pattern for T₈₀ could obtain ideal cane yield and benefit.

Abundant germplasm resources are the basis for mango variety breeding and industrial development. For better protection and utilization of mango germplasm resources, the TP-M13-SSR marker developed by our team previously were used to analyze the genetic diversity and construct molecular ID of 145 mango germplasms containing local cultivars, bred varieties and wild relative species, which stored in the nursery of Guangxi Innovation Base of mango germplasm resources conservation. The results showed that the average number of observed alleles for the 12 primer pairs was 3.2838, the average observed heterozygosity (H_o) was 0.5858, the average expected heterozygosity (H_e) was 0.6725, the average Shannon index (I) was 1.3383, and the average Nei's gene diversity index (N_a) was 0.6702. The polymorphism information content (PIC) of the 12 primer pairs ranged from 0.5036 to 0.7827, with an average value of 0.6396. All the primers were highly polymorphic sites. The result suggested that TP-M13-SSR primer could provide data support for genetic diversity analysis of mango. The genetic similarity coefficient of 145 materrials varied from 0.5676 to 1.000, with an average of 0.7417. The genetic similarity coefficient between Irwin and Indian No. 1 was 1.000. The minimum genetic similarity coefficient was 0.5676, between M. persiciformis 20-2 and Dadouxiang mango, M. persiciformis 20-2 and Shuoshuai mango, Jinhuang mango and Guire 10-1 mango. All the 145 mango germplasms were divided into two groups when the genetic similarity coefficient was 0.7060. Group I contained 108 mango species and 20 M. persiciformis species, accounting for 88.90% of the total number of germplasms. Group Ⅱ contained 17 specimens, all of which were M. persiciformis species. Group I could be further divided into five subgroups when the genetic similarity coefficient was 0.7330, among which subgroups I-1 and I-3 were the most abundant, accounting for 91.92% of all mango germplasms. The results of UPGMA clustering analysis showed that M. persiciformis were not clustered strictly according to the species relationship, and the overall clustering result of mango germplasms was basically consistent with its geographical origin. All the 145 materials were amplified by 12 pairs of SSR fluorescent primers to obtain the fingerprint map, and the molecular ID was obtained by the assignment of numbers and letters combination. Each pair of primers could distinguish 12.4 germplasms on average, and the identification rate was significantly higher than that of previous studies, indicating that TP-M13-SSR had more advantageous than denaturing polyacrylamide gel electrophoresis in mango germplasm identification. This study would provide scientific basis for the collection and utilization of germplasm resources and variety breeding of mango. It is also proposed for molecular identification of bred varieties, which is of great significance to the development of mango industry for providing methods for molecular identification and intellectual property of bred varieties.

Eight germplasm resources of Camellia sect. Chrysantha from Daweishan Mountain of Yunnan province were studied to provide scientific basis and research materials for the exploitation and utilization of Camellia plants. In this study, the leaf length and width of 13 cultivars of Camellia sect. Chrysantha were evaluated by direct observation of leaf phenotype, using five known germplasm resources as the control and mature leaves as the test materials, the content of six mineral elements (Cu, Zn, Fe, Mn, Ca, Mg) was determined by the wet ashing method, the contents of four functional components (tea polyphenols, total polysaccharides, total saponins and total flavonoids) were determined by the UV photometer method, the relationship between them and germplasm resources of Camellia sect. Chrysantha was analyzed by the cluster analysis. The results showed that the leaf shape of 13 Camellia sect. Chrysantha could be divided into two types: elliptic and oblong, and there were great differences in leaf area, leaf color and leaf serration. The highest and lowest content of Cu, Zn, Fe, Mn, Ca and Mg in leaves was 2.1, 1.9, 4.3, 6.6, 1.4 and 1.8 times, respectively. The content of total saponins, tea polyphenols, polysaccharides and flavonoids was 10.9, 5.8, 5.0 and 2.0 times, respectively. The correlation analysis showed that tea polyphenols had a significant negative correlation with leaf length/leaf width, a significant positive correlation with leaf color and leaf quality, and a significant negative correlation with leaf length/leaf width and zinc, there were significant positive correlations between leaf color and manganese, villi and copper. The results of cluster analysis showed that the 13 germplasm resources could be divided into 5 groups when the distance coefficient was 4.5, group I (including ‘Honghe 1’ Camellia sect. Chrysantha, JHC-2, JHC-3, JHC-4) and Group IV (including ordinary Camellia sect. Chrysantha, JHC-8, Camellia pubipetala Wan et Huang) contained relatively high contents of the constituents, JHC-2 and JHC-8 may have higher medicinal and health-care functions, but the mineral element contents and contents were generally higher, so the later development and utilization value was higher. The results of this study would be useful for further studies on the accumulation mechanism of important functional components in Camellia sect. Chrysantha, it would also provide theoretical basis for breeding new varieties of Camellia and further development and utilization of Camellia group plants in the future.

Ca²⁺ is a second messenger in plant cells, and Ca²⁺-ATPase (ACA/ECA), as an important protein in Ca²+transport, plays a crucial role in ensuring the balance of intracellular calcium ions and abiotic stress in plants. To investigate the biological function of Ca²⁺-ATPase (ACA/ECA) in Hevea brasiliensis, 45 ACA/ECA gene family members were identified from the rubber tree genome using the ACA/ECA protein sequence of the model plant Arabidopsis as a probe, including 38 ACA members and 7 ECA members. Expasy and Plant-mPLoc were used to comprehensively analyze the physicochemical properties, gene structure, chromosomal localization, phylogeny, and expression patterns of the 45 members. Physicochemical properties analysis showed that the number of amino acids encoded by each member was 86-1142, the molecular weight of amino acids ranged from 10 048.04 to 125 412.75 Da, and the protein products were mostly localized on the cytoplasmic membrane, with a few members localized on the endoplasmic reticulum, chloroplast, vacuole, and nucleus. In evolutionary, members of the ACA/ECA family were clearly clustered into ACA and ECA two branches, and rubber tree members were always in close proximity to cassava in both branches, indicating that there was a close relative between rubber tree and cassava during phylogeny. Chromosomal localization revealed that the 45 members of the ACA/ECA family were unevenly distributed across 14 chromosomes and one contig in rubber tree, in which, chromosomes 2 and 9 had the largest member distribution of 11 members. Expression analysis showed that there were obvious differences in the expression of some members in different groups, HbACA31 was expressed the most in leaves, HbACA36 was expressed the most in latex, and the expression of HbACA36 was obviously up-regulated in latex after treatment with ethenol. In addition, we also analyzed the influence of tapping on ACA/ECA gene expression, and found that HbACA36 was at a high expression level during tapping of the two rubber tree varieties, PR107 and Reyan 8-79, and significantly up-regulated during tapping of high-yield variety Reyan 8-79, which speculated that HbACA36 was involved in the regulation of rubber biosynthesis and played an important role. The results presented in this study reveal the physicochemical properties and expression patterns of ACA/CA family members for the first time in rubber tree, and would provide a foundation for further investigation of the biological functions of ACA/ECA genes in H. brasiliensis, especially in the regulation of the rubber production.