Characterisation of cultivated breeding lines of eggplant (Solanum melongena L.) and related wild Solanum species from India

Immature fruit of cultivated species of eggplant (Solanum melongena L.) are commonly used as a summer vegetable in India. Rich morphological variation exists among the cultivated species of eggplant in different growing regions of the country. We have characterised 24 breeding lines of Solanum spp., including 20 eggplant cultivars and four wild species of eggplant, based on 13 morphological characters using Mahalonabis D² statistics. All 24 breeding lines of Solanum spp., including the 20 eggplant cultivars and four wild species, were grouped into four clusters by agglomerative clustering. Cluster II and Cluster IV contained the most accessions (eight each), while Cluster I and Cluster III had four accessions each. The highest inter-cluster (D²) distance (158.33) was observed between Cluster I and Cluster II, followed by Cluster I and Cluster III (108.48), and Cluster II and Cluster IV (102.96), which indicated that accessions in Cluster I and Cluster II were more divergent than those in the other clusters. The highest intra-cluster distance (5.80) was observed in Cluster IV, with eight genotypes, and the lowest intra-cluster distance (2.21) was observed in Cluster II, also with eight genotypes. The intra-cluster distances in all four clusters were lower than the inter-cluster distances, which indicated that genotypes within the same cluster were closely related. Genotypes in Cluster IV had the maximum number of flowers per cluster (3.63), the highest number of fruit per cluster (3.25), and number of fruit per plant (208.63), which revealed that genotypes could be selected from Cluster IV for these characters. The first three principal components (PC1, PC2, and PC3) accounted 73.99% of the total variation among the 24 genotypes. These phenotypic data increase the feasibility of prioritising breeding lines in a crossing programme based on the uniqueness of their desirable morphological traits.     

茄子耐热性遗传表现

 采用4 份耐热性不同的茄子亲本半轮配法配制4 ×4 双列杂交, 对P₁ 、P₂ 、F₁ 、F₂ 、BC₁ 等5 个世代四叶期幼苗在温室内进行高温(平均昼/ 夜温度38. 8/ 24. 2 ℃) 处理, 同期田间栽培(平均昼/ 夜温度34. 4/ 22. 6 ℃) 。采用Hayman’s 法分析苗期耐热指数和成株期坐果率的调查数据, 表明, 茄子耐热性为不完全显性遗传, 受两对以上基因控制, 符合加性—显性模型, 其中加性效应占更主要成分。据此提出了耐热性选择方法。     

Nitric oxide alleviates adverse salt-induced effects by improving the photosynthetic performance and increasing the anti-oxidant capacity of eggplant (Solanum melongena L.)

Summary

Nitric oxide (NO) is an active molecule involved in many physiological functions in plants. To characterise the roles of NO in the tolerance of eggplant (Solanum melongena L.) to salt stress, the protective effects of exogenous sodium nitroprusside (SNP), a donor of NO, applied at different concentrations (0, 0.05, 0.1, or 0.2 mM), on plant biomass, photosynthesis, and anti-oxidant capacity were evaluated. The application of SNP alleviated the suppression of growth in eggplant under salt stress, as reflected by a higher accumulation of biomass. In parallel with growth, the application of SNP to salt-stressed plants resulted in enhanced photosynthetic parameters such as the net photosynthetic rate (P_n), stomatal conductance (g_s), transpiration rate (T_r), and intercellular CO₂ concentration (C_i), as well as an increased quantum efficiency of PSII (F_v/F_m), efficiency of excitation capture of open PSII centres (F_v’/F_m’), quantum yield of PSII ( _psii) and photochemical quenching coefficient (qP). Furthermore, exogenous SNP also reduced significantly the rate of production of O₂^{? –} radicals and the concentrations of malondialdehyde (MDA) and H₂O₂. It also increased the activities of superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) in eggplant leaves grown under salt stress. The results indicated that the protective effects of NO against salt stress in eggplant seedlings were most likely mediated through improvements in photosynthetic performance and the stimulation of anti-oxidant capacity.