Assessment of Nutritional Status of Guava Seedlings using Preliminary DRIS Norms and Sufficiency Ranges

The objective of this work was to propose preliminary Diagnosis and Recommendation Integrated System (DRIS) norms and derive critical levels and nutrient sufficiency ranges in the leaves of guava plants in commercial nursery conditions. Sixty-eight leaf samples were evaluated from fertilization trials with seedlings. In the low-yield subpopulation (84% of the population), the limiting nutrients by deficiency in descending order were nitrogen (N)> copper (Cu)>phosphorus (P) = potassium (K)> manganese (Mn)> iron (Fe) = zinc (Zn)> sulfur (S)> boron (B) = magnesium (Mg)> calcium (Ca), and the limiting ones by excess in descending order were B > Ca > Fe > Mn > S > Mg > Cu > P > Zn > N = K. The ranges of the appropriate DRIS indices were 24 to 28, 2.4 to 3.1, 21 to 29, 6 to 8, 1.9 to 2.9 and 1.9 to 2.3 (g kg^?1) for the macronutrients N, P, K, Ca, Mg and S, respectively, and 35 to 48, 4 to 15, 68 to 93, 31 to 60 and 180 to 245 (mg kg^?1) for the micronutrients B, Cu, Fe, Mn and Zn, respectively. The dry matter production of guava seedlings was associated with the nutritional status.     

金沙江干热河谷旱地番石榴生长规律及其与气象因子的关系

对金沙江干热河谷旱地番石榴树体、正造果、番花果生长规律及平均气温、最高气温、最低气温、相对湿度、降雨量、平均地温、最高地温、最低地温、日照时数、蒸发量等气象因子对月生长量的影响进行了研究，结果表明：株高、茎粗、枝展、果实纵径、横径累积生长量均呈曲线型；株高与最高地温和日照时数、枝展与相对湿度负相关，茎粗与相对湿度、降雨量正相关，其它因子对它们的影响相反．株高与茎粗、枝展正相关．茎粗与枝展互为负相关；各因子对纵横径的影响一致，正造果与最高气温及相对湿度和降雨量、番花果与相对湿度正相关．均与谢花后天数负相关，其它因子对它们的影响相反，纵横径互为正相关。     

番石榴叶片对不同程度水分胁迫的生理响应

研究珍珠番石榴(Psidium guajava L.)在不同程度水分胁迫下的生理变化,以期为番石榴节水栽培提供理论依据。以2年生珍珠番石榴为试材,通过水分胁迫处理,即对照为正常浇水,处理为不浇水,取不同胁迫天数植株中部成熟叶片,测定其中影响活性氧代谢的酶类含量和膜质过氧化作用的变化情况。结果表明:水分胁迫下,番石榴叶片过氧化物酶(POD)活性上升,超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性先升后降,抗坏血酸(ASA)含量下降,同时丙二醛(MDA)含量呈明显上升趋势。番石榴在不同程度水分胁迫下会产生各种生理反应,表现为影响活性氧代谢的各种酶类含量的变化与膜质过氧化作用增强。栽培番石榴适宜灌水间隔期为25～30d。     

Guava (Psidium guajava L.) trees in a pasture: population model,sensitivity analyses,and applications

A preliminary demographic model is presented for a population of guava (Psidium guajava L.) trees in a pasture. In this paper special attention is devoted to describing both the calculation and testing of the parameters of the model. Some applications of the model are described. It is predicted that the guava population will gradually decline; low seedling survival (due to chemical control of pasture weeds) seems to be the factor governing this trend. Preliminary analyses of total gross energy production and economic income, with and without the guavas, favours the presence of the trees in pastures.     

番石榴的综合利用现状及发展前景

介绍了番石榴果实、种子和花粉等的营养成分,研究了番石榴在食品、医药、保健等行业中的综合利用现状,并对番石榴在我国的发展前景提出了建议。     

Role of asiatic acid in treatment of insulin resistance in mouse adipocytes

AIM：To investigate the effects of asiatic acid, one of triterpenoids from Psidium guajava leaves, on the proliferation and differentiation of 3T3-L1 preadipocytes, and glucose and lipid metabolism of insulin-resistant adipocytes. METHODS：The proliferation of 3T3-L1 preadipocytes was tested by MTT assay, and the accumulation of lipid droplets in differentiated preadipocytes was measured by oil red O staining. The insulin-resistant cell model was established by exposure of the cells to dexamethasone. The cellular glucose uptake was determined by glucose oxidase-peroxidase assay. The free fat acid (FFA) concentration was detected by colorimetric method. Secreted adiponectin were measured by ELISA. The protein levels of peroxisome proliferator-activated receptor γ (PPARγ) and protein tyrosine phosphatase 1B (PTP1B) in insulin-resistant adipocytes were analyzed by Western blotting. RESULTS：Compared with medium group, asiatic acid increased the proliferation of 3T3-L1 preadipocytes and inhibited their differentiation at a concentration range of 10~100 μmol/L (P<0.05 or P<0.01). At concentrations of 30 μmol/L and 100 μmol/L, asiatic acid enhanced cellular glucose uptake in the insulin-resistant adipocytes both in basic and insulin-stimulation states. Asiatic acid decreased FFA production (P<0.05), and down-regulated the protein expression of PTP1B (P<0.05, or P<0.01). However, no effect on the secretion of adiponectin and the protein expression of PPARγ was observed (P>0.05). CONCLUSION：Asiatic acid enhances glucose uptake and inhibits FFA production in insulin-resistant adipocytes via down-regulating the protein expression of PTP1B, all of which play the roles of increasing insulin signaling sensitivity to improve insulin resistance.     

Monitoring Nutrient Status of Guava Fruit Trees in Punjab,Northwest India through the Diagnostic and Recommendation Integrated System Approach

Abstract

The Diagnostic and Recommendation Integrated System (DRIS) was employed for interpreting nutrient analyses of leaf tissue of guava fruit trees (Psidium guajava L.) cultivated in Punjab, northwest India. Standard reference DRIS norms were established for various nutrient ratios and used to compute DRIS indices, which assessed nutrient balance and order of limitation to yield. The DRIS evaluation and sufficiency range approach were equally effective and in agreement for diagnosing deficiencies of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sulfur (S), manganese (Mn), zinc (Zn), and copper (Cu). The results also show that the position of leaf tissue sampled does not have a major effect on the DRIS diagnosis. Nutrient sufficiency ranges derived from DRIS norms were 1.41–1.65, 0.10–0.17, 0.51–0.97, 1.16–2.12, 0.31–0.51, 0.18–0.28% for N, P, K, Ca, magnesium (Mg), and S and were 105–153, 58–110, 15–29, and 6–16 mg Kg^?1 for iron (Fe), Mn, Zn, and Cu, respectively. According to these sufficiency ranges 35, 62, 51, 75, 70, and 68% of samples were sufficient, and 4, 29, 36, 9, 10, and 22% of samples were low in N, P, K, Ca, Mg, and S, respectively. More than 50 and 2% of the guava trees selected for sampling was found to deficient in N and P, respectively. For micronutrients, 15, 6, and 7% of samples were found to be low in Mn, Zn, and Cu.     

番石榴焦腐病菌LAMP检测方法的建立及应用

 以钙黄绿素（calcein）为指示剂,建立了番石榴焦腐病菌（Botryosphaeria rhodina）的环介导等温扩增（Loop mediated isothermal amplification, LAMP）可视化快速检测方法。在该方法中,以番石榴焦腐病菌特异的核糖体转录间隔区（Internal transcribed spacer, ITS）序列为目的DNA片段,设计4条引物（2条内引物、2条外引物）,优化LAMP反应条件和反应体系,并进行特异性和灵敏度验证。研究确定最佳反应温度为64℃,反应时间1 h;特异性检测结果显示,15株不同地理来源的番石榴焦腐病菌和10份番石榴焦腐病病果组织LAMP产物均为阳性（绿色）,而26株其它病原菌及10份健康番石榴果实组织LAMP产物均为阴性（橘黄色）;灵敏度验证结果显示,该方法的检测灵敏度在DNA水平上可达到10 pg。实验结果表明,快速、准确、灵敏的LAMP检测方法适合基层部门及田间检测番石榴焦腐病菌使用。     

番石榴叶止泻机制的初步研究

用80%酒精提取番石榴叶中的有效成分, 观察提取物对细菌和离体小肠的作用。结果表明: 提取物能抑制大肠杆菌等6种病原菌生长; 降低家兔十二指肠、空肠、回肠等三肠段收缩张力。     

Direct and indirect effects of seed related characters on number of seed in guava (Psidium guajava L.) fruits

Dessert quality of guava fruit is considerably reduced by high seed content. Number of seeds in guava is associated with different seed and fruit characters. Influence of different seed characters on number of seeds per fruit (NSPF) was studied by analysing character association and direct and indirect effects on NSPF and seed related traits for 68 genotypes of guava collected from diverse sources and conserved at National Active Germplasm Site, CISH, Lucknow. Seed related characters were studied at the colour break stage of the fruits using image analysis software for counting number of seeds. The data was subjected to path analysis to find out direct and indirect effects of different characters on number of seeds in the fruits. At genotypic and phenotypic levels, NSPF was significantly and positively associated with seed weight per fruit (SWPF), number of seeds 100 g⁻¹ pulp (NSPHP) and fruit weight (FW). The genotypic (0.0029) and phenotypic (0.0563) residual values were fairly very low, which revealed that variables included in this study had significant contribution in determining NSPF. The NSPHP exhibited high positive direct effect on NSPF. The maximum direct response (P = 0.737, G = 1.004) of this component was attributed to the indirect positive effects of the SWPF and fruit:seed weight proportion (FSWP). SWPF also had a very high positive direct effect (P = 0.521, G = 0.694) on the NSPF. Correlation and path coefficient analysis revealed that SWPF, NSPHP and 100-seed weight (100SW) were deciding factors for realizing improvement for NSPF. The importance of small seeded genotypes in selection of less seeded varieties was emphasized.