The somaclone, C39, derived by tissue culture from the obligate apomict Paspalum dilatatum cv Raki (2n=50), had 50 chromosomes and a karyotype apparently identical to Raki.SC2 seedlings of C39 showed a high degree of ...The somaclone, C39, derived by tissue culture from the obligate apomict Paspalum dilatatum cv Raki (2n=50), had 50 chromosomes and a karyotype apparently identical to Raki.SC2 seedlings of C39 showed a high degree of phenotypic variation which was of ten associated with increased chromosome numbers, but some of the variant seedlings were karyotypically indistinguishable from Raki or C39. Plants with increased chromosome numbers exhibited a high degree of intraplant chromosome variation (aneusomaty). In one of the SC2seedlings, the chromosome number of root tip cells varied from 58 to 82 and in several other seedlings the range was more than 10. The results suggested that the ability to form seed apomictically was much reduced in C39 and that this plant showed some capacity for sexual reproduction and the resulting seedlings, with a chromosome number of about 70, were genetically unstable. Of 11 SC2 seedlings examined cytolog ically, 6 did not produce any viable seed. Seedlings grown from seed of the remaining 5 plants showed that aneusomaty persisted in the SC3 generation. SC3 seedlings which were phenotypically similar to their maternal parent showed a similar range of chromosome numbers to that parent. Some of the SC3 seedlings exhibited an even wider range of chromosome numbers (e.g.56-136), and these plants were all dwarfs.展开更多
A survey was conducted in 2011 in the major date growing regions of Saudi Arabia to identify and evaluate date palms with fruit characteristics preferred by the producers and consumers. The regions in the Kingdom surv...A survey was conducted in 2011 in the major date growing regions of Saudi Arabia to identify and evaluate date palms with fruit characteristics preferred by the producers and consumers. The regions in the Kingdom surveyed for this purpose were Al-Zulfi, Al-Hassa, Najran, Al-Madinah Al-Munawarah and AI-Qassim. Seventy palms from seedlings were initially identified for the study based on the following fruit characteristics, i.e., fruit length, breadth, weight, color, taste, texture, sugar content, external appearance and also the market value. Subsequently, 12 palms （Al-Afiah, Duhiba, Adbah, Aliah, Shamshula, Masifat Al-Asedy, Suwaid, Batlyah, AI-Nassar, Hussan, Sukariyat Al-Zulfi and Al-Hamat） mainly from the Zulfi and Riyadh regions were found to meet the required standards with potential for commercial date farming. Among these, fruits of Adbah had the highest total sugars of 72.9% followed by Duhiba with a total sugar content of 71.9%. Fruit length was maximum （49.1 mm） in the variety Allah, while the fruits of the variety Hussan recorded the maximum weight of 19.5 g. Furthermore, it is pertinent to mention that fruit size of the 12 selected cultivars was generally large and comparable to Majdool, a well-known date palm cultivar of North Africa. The fruits of the selected cultivars were also tasty and can be stored separately.展开更多
文摘The somaclone, C39, derived by tissue culture from the obligate apomict Paspalum dilatatum cv Raki (2n=50), had 50 chromosomes and a karyotype apparently identical to Raki.SC2 seedlings of C39 showed a high degree of phenotypic variation which was of ten associated with increased chromosome numbers, but some of the variant seedlings were karyotypically indistinguishable from Raki or C39. Plants with increased chromosome numbers exhibited a high degree of intraplant chromosome variation (aneusomaty). In one of the SC2seedlings, the chromosome number of root tip cells varied from 58 to 82 and in several other seedlings the range was more than 10. The results suggested that the ability to form seed apomictically was much reduced in C39 and that this plant showed some capacity for sexual reproduction and the resulting seedlings, with a chromosome number of about 70, were genetically unstable. Of 11 SC2 seedlings examined cytolog ically, 6 did not produce any viable seed. Seedlings grown from seed of the remaining 5 plants showed that aneusomaty persisted in the SC3 generation. SC3 seedlings which were phenotypically similar to their maternal parent showed a similar range of chromosome numbers to that parent. Some of the SC3 seedlings exhibited an even wider range of chromosome numbers (e.g.56-136), and these plants were all dwarfs.
文摘A survey was conducted in 2011 in the major date growing regions of Saudi Arabia to identify and evaluate date palms with fruit characteristics preferred by the producers and consumers. The regions in the Kingdom surveyed for this purpose were Al-Zulfi, Al-Hassa, Najran, Al-Madinah Al-Munawarah and AI-Qassim. Seventy palms from seedlings were initially identified for the study based on the following fruit characteristics, i.e., fruit length, breadth, weight, color, taste, texture, sugar content, external appearance and also the market value. Subsequently, 12 palms （Al-Afiah, Duhiba, Adbah, Aliah, Shamshula, Masifat Al-Asedy, Suwaid, Batlyah, AI-Nassar, Hussan, Sukariyat Al-Zulfi and Al-Hamat） mainly from the Zulfi and Riyadh regions were found to meet the required standards with potential for commercial date farming. Among these, fruits of Adbah had the highest total sugars of 72.9% followed by Duhiba with a total sugar content of 71.9%. Fruit length was maximum （49.1 mm） in the variety Allah, while the fruits of the variety Hussan recorded the maximum weight of 19.5 g. Furthermore, it is pertinent to mention that fruit size of the 12 selected cultivars was generally large and comparable to Majdool, a well-known date palm cultivar of North Africa. The fruits of the selected cultivars were also tasty and can be stored separately.
