Khan Abdul Latif, Al-Harrasi Ahmed, Numan Muhammad, AbdulKareem Noor Mazin, Mabood Fazal, Al-Rawahi Ahmed
Natural & Medical Sciences Research Center, University of Nizwa, Nizwa 616, Oman.
Department of Biology, University of North Carolina, Greensboro, NC 27402-6170, USA.
Plants (Basel). 2021 Mar 12;10(3):536. doi: 10.3390/plants10030536.
(date palm) is a well-known nutritious and economically important fruit tree found in arid regions of the Middle East and North Africa. Being diploid, it has extremely high divergence in gender, where sex differentiation in immature date palms ( L.) has remained an enigma in recent years. Herein, new robust infrared (near-infrared reflectance spectroscopy (NIRS) and Fourier transform infrared attenuated total reflectance (FTIR/ATR)) and nuclear magnetic resonance (NMR) spectroscopy methods coupled with extensive chemometric analysis were used to identify the sex differentiation in immature date palm leaves. NIRS/FTIR reflectance and H-NMR profiling suggested that the signals of monosaccharides (glucose and fructose) and/or disaccharides (maltose and sucrose) play key roles in sex differentiation. The three kinds of spectroscopic data were clearly differentiated among known and unknown male and female leaves via principal component and partial least square discriminant analyses. Furthermore, sex-specific genes and molecular markers obtained from the lower halves of LG12 chromosomes showed enhanced transcript accumulation of mPdIRDP52, mPdIRDP50, and PDK101 in females compared with in males. The phylogeny showed that the mPdIRD033, mPdIRD031, and mPdCIR032 markers formed distinctive clades with more than 70% similarity in gender differentiation. The three robust analyses provide an alternative tool to differentiate sex in date palm trees, which offers a solution to the long-standing challenge of dioecism and could enhance in situ tree propagation programs.
海枣是一种在中东和北非干旱地区广为人知的营养丰富且具有重要经济价值的果树。作为二倍体，它在性别上具有极高的差异，近年来未成熟海枣（Phoenix dactylifera L.）的性别分化一直是个谜。在此，结合广泛的化学计量分析，使用了新的强大的红外（近红外反射光谱法（NIRS）和傅里叶变换红外衰减全反射法（FTIR/ATR））以及核磁共振（NMR）光谱方法来识别未成熟海枣叶片的性别分化。NIRS/FTIR反射率和氢核磁共振谱分析表明，单糖（葡萄糖和果糖）和/或二糖（麦芽糖和蔗糖）的信号在性别分化中起关键作用。通过主成分分析和偏最小二乘判别分析，在已知和未知的雄性和雌性叶片之间能够清晰地区分这三种光谱数据。此外，从LG12染色体下半部分获得的性别特异性基因和分子标记显示，与雄性相比，雌性中mPdIRDP52、mPdIRDP50和PDK101的转录积累增强。系统发育分析表明，mPdIRD033、mPdIRD031和mPdCIR032标记在性别分化中形成了独特的分支，相似度超过70%。这三种强大的分析提供了一种区分海枣树性别的替代工具，为长期存在的雌雄异株挑战提供了解决方案，并可加强原地树木繁殖计划。
